Make Teutonic Knights usable without buffing Teutons

It depends a bit on what you are fighting though. Even with the +2 armor for the teutons, the champions will take much more damage from most melee whereas TKs reduce the damage significantly with higher HP. They are also more population efficient and while they are slower than champions, it’s 0.1 speed difference which is noticeable but not a massive issue guarding siege. That being said agree that the +2 armor for the champions does reduce the situations where you would use TKs.

I think one solution that would be interesting would be to extend supplies to unique infantry units. Probably would need to reduce the effect for Karambits but would increase viability of unique infantry units