Cavalier really comes into it's own when mixed with the courtier class, as courtier's desperately need honour to field useful units and the troop bonus is applied across the board for a cavalier, which means that a C/C can field at least 20 men.
If you have a loosely controlled area with archers or MI, you can control and upkeep a sizable chunk without the need for army support.
That is a terrible reason to select a class.
