Quote Originally Posted by Akka
It's very simple : each province has a certain pool of mercenaries you can recruit. Once you've recruited them, they take a certain time to "regenerate".
That's it :)
Well, yes that would just about explain it. It doesn't explain the mechanic though does it? I was hoping for a bit more of a scientific answer to be honest...

How is the pool comprised?
Are some provinces more likely to yield mercs than others?
How are the units for each province decided upon?

Cheers,

Rob.