You can actually, believe it or not get them all. You just have to ever so often stop by the tavern and buy booze for them to keep their happiness up. Outside of that, yeah. I made my character an int/cha based, and I got all of the heroes, and 15 Leadership, and I just let my Heroes over run the enemy. Even the Int/Charisma based heroes, I just went straight strength/Agility on them ignoring their int/Charisma. Lol, so all of my heroes are fighters while I take care of the surgery, and what not.