Very true, so much easier to swell your coffers by exterminating. I hope that the option to press into service is added

.......Orda
That would be awesome!!!

Or they could make it more rewarding, by adding pillageable unwalled villages in every province. If you for example were too raid one of these villages the owner of the province would loose tax income for a certain amount of turns while you would gain some cash from looting. This would make raiding more realistic as a raiding party would no longer need to lay siege to a city and conquer a province just to do some raiding, nor would a raiding power need the manpower to perform an assault.
This is another great idea. It would make the rebels seem less of an anoyance and more of an urgency to get rid of. It would make the game more rewarding too for the smaller factions like the Welsh and the Irish because they could gain income by raiding without having to build a huge unsupportable army to take a castle.

Both these options would make the game more fun and realistic.