When playing as the Holy Roman Empire i altered the desc_strat file, making it so the HRE start the campaign with several Teutonic Knights, also made it possible for that faction to recruit them without having a chapter house.
However when it came to fighting a battle with them i noticed something odd. The knights were cavalry units, without soldiers upon the mounts. All you would see in battle would be a squad of armoured horses without riders going about killing people.

I don't know whether this happened because the faction lacks the chapter house or not, but if anybody knows how the sort this problem out i'd be very grateful, as it is rather annoying.

Thanks.