From my FAQ

How many companions are there? Where do you get them?
There are a grand total of 29 companions in this mod. 3 “noblemen” from every culture (Catholic, Eastern Orthodox, Mongol, Islam and Baltic)
To obtain these 3 noblemen from every culture, you must own a village which was originally land of that culture at the start of the mod.
Alternatively, using cheatmenu will let you recruit noblemen from villages you don’t own.
There are 14 mercenary companions in this mod. These are recruitable for a fee from the menu in any major town.

If you're giving lands to any companions, give it to the "noblemen"