But what *less* can they do? They can do just the same as everyone else, they are just less effective at it.
You know, I really didn't think I'd have to explain the difference between a 15 man unit and a 40 man unit. If we assume a unit with good training, over 70% cohesion, and over 60 weapon and armor, a 15 man unit will have about 300 CS. A 40 man unit will have over 600 CS. You only hurt your own realm by giving your knight a crappy tax rate.