I have two geldings. One is 14 and the boss. The other is a 3 year old and would like to be boss. If I bring home another horse, say a gentle older mare, what could I expect from my two boys? I really need them to all be in the same pasture, though I don't mind seperating them at first. I don't want the mare to be hurt. Is 3 a crowd? Is there any combo I could start with that would make it easier? Can the boy/girl thing ever work?