diff --git a/zig-ecs/src/ecs/groups.zig b/zig-ecs/src/ecs/groups.zig
index 95c30f7..8a76b43 100644
--- a/zig-ecs/src/ecs/groups.zig
+++ b/zig-ecs/src/ecs/groups.zig
@@ -73,37 +73,27 @@ pub fn BasicGroup(comptime n_includes: usize, comptime n_excludes: usize) type {
     };
 }
 
-pub fn OwningGroup(comptime n_owned: usize, comptime n_includes: usize, comptime n_excludes: usize) type {
-    return struct {
-        const Self = @This();
-
-        current: *usize,
-        super: *usize,
-        registry: *Registry,
-        owned_type_ids: [n_owned]u32,
-        include_type_ids: [n_includes]u32,
-        exclude_type_ids: [n_excludes]u32,
-
-        pub fn init(super: *usize, current: *usize, registry: *Registry, owned_type_ids: [n_owned]u32, include_type_ids: [n_includes]u32, exclude_type_ids: [n_excludes]u32) Self {
-            return Self{
-                .super = super,
-                .current = current,
-                .registry = registry,
-                .owned_type_ids = owned_type_ids,
-                .include_type_ids = include_type_ids,
-                .exclude_type_ids = exclude_type_ids,
-            };
-        }
+pub const OwningGroup = struct {
+    registry: *Registry,
+    group_data: *Registry.GroupData,
+    super: *usize,
+
+    pub fn init(registry: *Registry, group_data: *Registry.GroupData, super: *usize) OwningGroup {
+        return .{
+            .registry = registry,
+            .group_data = group_data,
+            .super = super,
+        };
+    }
 
-        pub fn len(self: Self) usize {
-            return self.current.*;
-        }
+    pub fn len(self: OwningGroup) usize {
+        return self.group_data.current;
+    }
 
-        pub fn sortable(self: *Registry, comptime T: type) bool {
-            return self.super.* == n_owned + n_includes + n_excludes;
-        }
-    };
-}
+    pub fn sortable(self: OwningGroup, comptime T: type) bool {
+        return self.group_data.super == self.group_data.size;
+    }
+};
 
 test "BasicGroup creation" {
     var reg = Registry.init(std.testing.allocator);
@@ -133,7 +123,7 @@ test "BasicGroup excludes" {
     var reg = Registry.init(std.testing.allocator);
     defer reg.deinit();
 
-    var group = reg.group(.{}, .{ i32 }, .{ u32 });
+    var group = reg.group(.{}, .{i32}, .{u32});
     std.testing.expectEqual(group.len(), 0);
 
     var e0 = reg.create();
@@ -168,7 +158,7 @@ test "OwningGroup" {
     var reg = Registry.init(std.testing.allocator);
     defer reg.deinit();
 
-    var group = reg.group(.{i32, u32}, .{}, .{});
+    var group = reg.group(.{ i32, u32 }, .{}, .{});
 
     var e0 = reg.create();
     reg.add(e0, @as(i32, 44));
@@ -180,7 +170,7 @@ test "OwningGroup add/remove" {
     var reg = Registry.init(std.testing.allocator);
     defer reg.deinit();
 
-    var group = reg.group(.{i32, u32}, .{}, .{});
+    var group = reg.group(.{ i32, u32 }, .{}, .{});
 
     var e0 = reg.create();
     reg.add(e0, @as(i32, 44));
@@ -203,9 +193,9 @@ test "multiple OwningGroups" {
     // var group1 = reg.group(.{u64, u32}, .{}, .{});
     // var group2 = reg.group(.{u64, u32, u8}, .{}, .{});
 
-    var group5 = reg.group(.{Sprite, Transform}, .{Renderable, Rotation}, .{});
+    var group5 = reg.group(.{ Sprite, Transform }, .{ Renderable, Rotation }, .{});
     var group3 = reg.group(.{Sprite}, .{Renderable}, .{});
-    var group4 = reg.group(.{Sprite, Transform}, .{Renderable}, .{});
+    var group4 = reg.group(.{ Sprite, Transform }, .{Renderable}, .{});
 
     var last_size: u8 = 0;
     for (reg.groups.items) |grp| {
diff --git a/zig-ecs/src/ecs/registry.zig b/zig-ecs/src/ecs/registry.zig
index d79cc60..3411c00 100644
--- a/zig-ecs/src/ecs/registry.zig
+++ b/zig-ecs/src/ecs/registry.zig
@@ -37,7 +37,7 @@ pub const Registry = struct {
     allocator: *std.mem.Allocator,
 
     /// internal, persistant data structure to manage the entities in a group
-    const GroupData = struct {
+    pub const GroupData = struct {
         hash: u64,
         size: u8,
         /// optional. there will be an entity_set for non-owning groups and current for owning
@@ -485,9 +485,7 @@ pub const Registry = struct {
         comptime const hash = comptime hashGroupTypes(owned, includes, excludes);
 
         for (self.groups.items) |grp| {
-            // TODO: these checks rely on owned/include/exclude to all be in the same order. fix that.
-            // TODO: prolly dont need the mem.eql since hash is the same damn thing
-            if (grp.hash == hash and std.mem.eql(u32, grp.owned, owned_arr[0..]) and std.mem.eql(u32, grp.include, includes_arr[0..]) and std.mem.eql(u32, grp.exclude, excludes_arr[0..])) {
+            if (grp.hash == hash) {
                 maybe_group_data = grp;
                 break;
             }
@@ -500,7 +498,7 @@ pub const Registry = struct {
                 return BasicGroup(includes.len, excludes.len).init(&group_data.entity_set, self, includes_arr, excludes_arr);
             } else {
                 var first_owned = self.assure(owned[0]);
-                return OwningGroup(owned.len, includes.len, excludes.len).init(&first_owned.super, &group_data.current, self, owned_arr, includes_arr, excludes_arr);
+                return OwningGroup.init(self, group_data, &first_owned.super);
             }
         }
 
@@ -577,7 +575,7 @@ pub const Registry = struct {
                 new_group_data.entity_set.add(entity);
             }
         } else {
-            // ??we cannot iterate backwards because we want to leave behind valid entities in case of owned types
+            // ??? why not? we cannot iterate backwards because we want to leave behind valid entities in case of owned types
             var first_owned_storage = self.assure(owned[0]);
             for (first_owned_storage.data().*) |entity| {
                 new_group_data.maybeValidIf(entity);
@@ -591,17 +589,18 @@ pub const Registry = struct {
             return BasicGroup(includes.len, excludes.len).init(&new_group_data.entity_set, self, includes_arr, excludes_arr);
         } else {
             var first_owned_storage = self.assure(owned[0]);
-            return OwningGroup(owned.len, includes.len, excludes.len).init(&first_owned_storage.super, &new_group_data.current, self, owned_arr, includes_arr, excludes_arr);
+            return OwningGroup.init(self, new_group_data, &first_owned_storage.super);
         }
     }
 
-    /// returns the Type that a view will be based on the includes and excludes
+    /// returns the Type that a view will be, based on the includes and excludes
     fn GroupType(comptime owned: var, comptime includes: var, comptime excludes: var) type {
         if (owned.len == 0) return BasicGroup(includes.len, excludes.len);
-        return OwningGroup(owned.len, includes.len, excludes.len);
+        return OwningGroup;
     }
 
-    /// given the 3 group Types arrays, generates a (mostly) unique u64 hash. Simultaneously ensures there are no duped types.
+    /// given the 3 group Types arrays, generates a (mostly) unique u64 hash. Simultaneously ensures there are no duped types between
+    /// the 3 groups.
     inline fn hashGroupTypes(comptime owned: var, comptime includes: var, comptime excludes: var) u64 {
         comptime {
             for (owned) |t1| {
@@ -623,10 +622,24 @@ pub const Registry = struct {
         }
     }
 
+    /// expects a tuple of types. Convertes them to type names, sorts them then concatenates and returns the string.
     inline fn concatTypes(comptime types: var) []const u8 {
         comptime {
+            const impl = struct {
+                fn asc(lhs: []const u8, rhs: []const u8) bool {
+                    return std.mem.lessThan(u8, lhs, rhs);
+                }
+            };
+
+            var names: [types.len][]const u8 = undefined;
+            for (names) |*name, i| {
+                name.* = @typeName(types[i]);
+            }
+
+            std.sort.sort([]const u8, &names, impl.asc);
+
             comptime var res: []const u8 = "";
-            inline for (types) |t| res = res ++ @typeName(t);
+            inline for (names) |name| res = res ++ name;
             return res;
         }
     }
diff --git a/zig-ecs/tests/groups_test.zig b/zig-ecs/tests/groups_test.zig
index ced5870..fda7110 100644
--- a/zig-ecs/tests/groups_test.zig
+++ b/zig-ecs/tests/groups_test.zig
@@ -72,5 +72,5 @@ test "nested OwningGroups entity order" {
 
     printStore(sprite_store, "Sprite");
     printStore(transform_store, "Transform");
-    warn("group2.current: {}\n", .{group2.current.*});
+    warn("group2.current: {}\n", .{group2.group_data.current});
 }