I have around 620 Leadership with my Paladin on Level 3 (got Grand Strategy Medal plus took Leadership I skill), I hope I can recruit at least one soon. They are also incredibly expensive... 15.000 Gold! More then Dragons even!
BTW - One correction to note. I have been using Assassins (and they are needed, Debir is crawling with Orcs!) and found out how the "Find Weakness" ability works. Unlike the description, which says you must destroy the enemy unit, it is actually enough to just attack them with Backstab or Murder. Each time you attack an enemy type, the damage bonus goes up by 5% - and unlike Favourite Enemy, this is possible for all kind of units! My Assassins already have 10% bonuses against orcs and goblins.
This makes taking care of them and not losing all of them all the more important.