What if, instead of forcing honour concepts on the player, the player is instead given choices to make their own interpretation?
I suggest that the Warrior Culture civic also unlocks an "Honour Code" policy which grants various bonuses at the cost of limiting other options
Options could include things like
- Victory (empire-wide happiness bonus when a war is won, empire-wide happiness malus when a war is lost)
- Holmgang (further increases army damage, while limiting orbital bombardment)
- Flower Wars (Undesirables are always set to forced labour, forced labour also produces unity)
- Firepower (bonuses to fleet combat, increased war exhaustion from space battles)
That way it'll be possible to expand on both gameplay and roleplay aspects of the civic.