You can't do that.Lancers should just replace knights for all of those civs. Would be historicly more accurate and would allow for some civ specific bonuses.
That's an interesting point. What do you think of removing the scout line from said civs, like they did with Gurjaras? Might have to balance things somewhat, but the devs need to do something about the unit anyhow.Steppe Lancers and Knights serve different purposes, Steppe Lancers are Light cavalry that are stronger in groups but are weaker vs archers, plus are able to hit villagers behind walls, Knights are overall better vs archers and to keep raiding.