diff --git a/tansu-server/src/coordinator/group.rs b/tansu-server/src/coordinator/group.rs
index f2edc13..400192e 100644
--- a/tansu-server/src/coordinator/group.rs
+++ b/tansu-server/src/coordinator/group.rs
@@ -13,14 +13,11 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+pub mod administrator;
 pub mod consumer;
-pub mod cooperative_sticky;
-pub mod range;
-pub mod round_robin;
-pub mod typestate;
 
 use crate::Result;
-use round_robin::{Fresh, Inner, RoundRobin, Wrapper};
+use administrator::{Controller, Fresh, Inner, Wrapper};
 use std::{collections::BTreeMap, fmt::Debug};
 use tansu_kafka_sans_io::{
     join_group_request::JoinGroupRequestProtocol,
@@ -193,7 +190,7 @@ pub struct GroupProvider;
 impl ProvideCoordinator for GroupProvider {
     fn provide_coordinator(&mut self) -> Result<Box<dyn Coordinator>> {
         let wrapper: Wrapper = Inner::<Fresh>::default().into();
-        Ok(Box::new(RoundRobin::new(wrapper)) as Box<dyn Coordinator>)
+        Ok(Box::new(Controller::new(wrapper)) as Box<dyn Coordinator>)
     }
 }
 
diff --git a/tansu-server/src/coordinator/group/round_robin.rs b/tansu-server/src/coordinator/group/administrator.rs
similarity index 97%
rename from tansu-server/src/coordinator/group/round_robin.rs
rename to tansu-server/src/coordinator/group/administrator.rs
index bc2c518..4ec797a 100644
--- a/tansu-server/src/coordinator/group/round_robin.rs
+++ b/tansu-server/src/coordinator/group/administrator.rs
@@ -35,7 +35,77 @@ use tracing::{debug, instrument};
 
 use crate::{Error, Result};
 
-use super::{typestate::Group, Coordinator};
+use super::Coordinator;
+
+pub trait Group: Debug + Send {
+    type JoinState;
+    type SyncState;
+    type HeartbeatState;
+    type LeaveState;
+    type OffsetCommitState;
+    type OffsetFetchState;
+
+    fn join(
+        self,
+        now: Instant,
+        group_id: &str,
+        session_timeout_ms: i32,
+        rebalance_timeout_ms: Option<i32>,
+        member_id: &str,
+        group_instance_id: Option<&str>,
+        protocol_type: &str,
+        protocols: Option<&[JoinGroupRequestProtocol]>,
+        reason: Option<&str>,
+    ) -> (Self::JoinState, Body);
+
+    fn sync(
+        self,
+        now: Instant,
+        group_id: &str,
+        generation_id: i32,
+        member_id: &str,
+        group_instance_id: Option<&str>,
+        protocol_name: Option<&str>,
+        assignments: Option<&[SyncGroupRequestAssignment]>,
+    ) -> (Self::SyncState, Body);
+
+    fn heartbeat(
+        self,
+        now: Instant,
+        group_id: &str,
+        generation_id: i32,
+        member_id: &str,
+        group_instance_id: Option<&str>,
+    ) -> (Self::HeartbeatState, Body);
+
+    fn leave(
+        self,
+        now: Instant,
+        group_id: &str,
+        member_id: Option<&str>,
+        members: Option<&[MemberIdentity]>,
+    ) -> (Self::LeaveState, Body);
+
+    fn offset_commit(
+        self,
+        now: Instant,
+        group_id: &str,
+        generation_id_or_member_epoch: Option<i32>,
+        member_id: Option<&str>,
+        group_instance_id: Option<&str>,
+        retention_time_ms: Option<i64>,
+        topics: Option<&[OffsetCommitRequestTopic]>,
+    ) -> (Self::OffsetCommitState, Body);
+
+    fn offset_fetch(
+        self,
+        now: Instant,
+        group_id: Option<&str>,
+        topics: Option<&[OffsetFetchRequestTopic]>,
+        groups: Option<&[OffsetFetchRequestGroup]>,
+        require_stable: Option<bool>,
+    ) -> (Self::OffsetFetchState, Body);
+}
 
 #[derive(Debug)]
 pub enum Wrapper {
@@ -455,11 +525,11 @@ impl Wrapper {
 }
 
 #[derive(Debug)]
-pub struct RoundRobin {
+pub struct Controller {
     wrapper: Option<Wrapper>,
 }
 
-impl RoundRobin {
+impl Controller {
     pub fn new(wrapper: Wrapper) -> Self {
         Self {
             wrapper: Some(wrapper),
@@ -467,7 +537,7 @@ impl RoundRobin {
     }
 }
 
-impl Coordinator for RoundRobin {
+impl Coordinator for Controller {
     fn join(
         &mut self,
         group_id: &str,
@@ -636,26 +706,6 @@ pub struct Forming {
     leader: Option<String>,
 }
 
-// impl From<Syncing> for Forming {
-//     fn from(value: Syncing) -> Self {
-//         Self {
-//             protocol_type: value.protocol_type,
-//             protocol_name: value.protocol_name,
-//             leader: Some(value.leader),
-//         }
-//     }
-// }
-
-// impl From<Formed> for Forming {
-//     fn from(value: Formed) -> Self {
-//         Self {
-//             protocol_type: value.protocol_type,
-//             protocol_name: value.protocol_name,
-//             leader: Some(value.leader),
-//         }
-//     }
-// }
-
 #[derive(Clone, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct Syncing {
     protocol_type: String,
diff --git a/tansu-server/src/coordinator/group/cooperative_sticky.rs b/tansu-server/src/coordinator/group/cooperative_sticky.rs
deleted file mode 100644
index 24cee70..0000000
--- a/tansu-server/src/coordinator/group/cooperative_sticky.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright ⓒ 2024 Peter Morgan <peter.james.morgan@gmail.com>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-#[allow(dead_code)]
-struct CooperativeSticky;
diff --git a/tansu-server/src/coordinator/group/range.rs b/tansu-server/src/coordinator/group/range.rs
deleted file mode 100644
index 402d28a..0000000
--- a/tansu-server/src/coordinator/group/range.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright ⓒ 2024 Peter Morgan <peter.james.morgan@gmail.com>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-#[allow(dead_code)]
-struct Range;
diff --git a/tansu-server/src/coordinator/group/typestate.rs b/tansu-server/src/coordinator/group/typestate.rs
deleted file mode 100644
index ca48f79..0000000
--- a/tansu-server/src/coordinator/group/typestate.rs
+++ /dev/null
@@ -1,94 +0,0 @@
-// Copyright ⓒ 2024 Peter Morgan <peter.james.morgan@gmail.com>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Affero General Public License as
-// published by the Free Software Foundation, either version 3 of the
-// License, or (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Affero General Public License for more details.
-//
-// You should have received a copy of the GNU Affero General Public License
-// along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-use std::{fmt::Debug, time::Instant};
-use tansu_kafka_sans_io::{
-    join_group_request::JoinGroupRequestProtocol,
-    leave_group_request::MemberIdentity,
-    offset_commit_request::OffsetCommitRequestTopic,
-    offset_fetch_request::{OffsetFetchRequestGroup, OffsetFetchRequestTopic},
-    sync_group_request::SyncGroupRequestAssignment,
-    Body,
-};
-
-pub(crate) trait Group: Debug + Send {
-    type JoinState;
-    type SyncState;
-    type HeartbeatState;
-    type LeaveState;
-    type OffsetCommitState;
-    type OffsetFetchState;
-
-    fn join(
-        self,
-        now: Instant,
-        group_id: &str,
-        session_timeout_ms: i32,
-        rebalance_timeout_ms: Option<i32>,
-        member_id: &str,
-        group_instance_id: Option<&str>,
-        protocol_type: &str,
-        protocols: Option<&[JoinGroupRequestProtocol]>,
-        reason: Option<&str>,
-    ) -> (Self::JoinState, Body);
-
-    fn sync(
-        self,
-        now: Instant,
-        group_id: &str,
-        generation_id: i32,
-        member_id: &str,
-        group_instance_id: Option<&str>,
-        protocol_name: Option<&str>,
-        assignments: Option<&[SyncGroupRequestAssignment]>,
-    ) -> (Self::SyncState, Body);
-
-    fn heartbeat(
-        self,
-        now: Instant,
-        group_id: &str,
-        generation_id: i32,
-        member_id: &str,
-        group_instance_id: Option<&str>,
-    ) -> (Self::HeartbeatState, Body);
-
-    fn leave(
-        self,
-        now: Instant,
-        group_id: &str,
-        member_id: Option<&str>,
-        members: Option<&[MemberIdentity]>,
-    ) -> (Self::LeaveState, Body);
-
-    fn offset_commit(
-        self,
-        now: Instant,
-        group_id: &str,
-        generation_id_or_member_epoch: Option<i32>,
-        member_id: Option<&str>,
-        group_instance_id: Option<&str>,
-        retention_time_ms: Option<i64>,
-        topics: Option<&[OffsetCommitRequestTopic]>,
-    ) -> (Self::OffsetCommitState, Body);
-
-    fn offset_fetch(
-        self,
-        now: Instant,
-        group_id: Option<&str>,
-        topics: Option<&[OffsetFetchRequestTopic]>,
-        groups: Option<&[OffsetFetchRequestGroup]>,
-        require_stable: Option<bool>,
-    ) -> (Self::OffsetFetchState, Body);
-}