IMO, in strategus all the players should play with the banner of the faction that they are mercing for.
It`s not such a big change, but it will help the immersion a bit.
That idea is soo old but now its getting some recognition, there are already blank banners in strat (well, atleast on the website).
There just need to be something like "set banner of your faction", strictly spliting cRPG Clans from Strategus Factions.
Or atleast including more banners to the game, but most of the factions will have the clans banner anyway, so not that much space needed.
It should also appear when the faction got 1 fief, if it got nothing it makes nearly nosense anyway, or they could actually select one of the native banners to have a unity in that if fighters might appear.