But why should other people choose to pay you? Any lord could knight his followers so why pay somebody else to do it when you could spend the money on your own army?
You may wanna let me know how many men you'll have then and how your going to support them.
You've gotta find a way to feed and arm them all, I can help with weapons but im going to need to import some food myself for the early game so i cant feed your men as well as mine so you either need to make your own deal and find a way to make money or give me some money and ill import food for you along with my own.
That's how feudalism works. If the Guild is supported by the Crown and a fief wants the Crown's protection, they would pay up. Aside from the knights not being part of the royalty with land and direct superiors in the government and stuff, that's how real-world feudalism worked.
Kedly: What do you mean by "slavers?"
Oh, and to clarify: The children in your realm are mostly too young to do much work. Maybe a third to half would be old enough to do basic work, like errands or apprenticeship, and most younger children would help their parents a little, but by the time they can be trusted to and are able to do hard work they are no longer, by this definition.
Also, this being the medieval era, most women will be housekeepers. You can have women work, but if less than, say, half of households have someone with enough time to take care of chores you're risking revolts, so the men will probably be most of the workers. I would have mentioned a caveat like this before, but I hadn't realised it until now. If you can't keep house, you won't be happy...
I have a feeling revolts will be a big thing at first...