Hi Lauren...good luck with your search. I just wanted to add my 2 cents. I have 3 boars together. Scooby is 2, Scooter is 1 and Emmet is 3 months. Scooter is the dominate boar so far. At least he was until Emmet came. Emmet is already getting a little bolder as he enters puberty. Who knows, the dynamics could change in the next few months. I don't suggest putting them in cages next to each other to see how it goes. It's like pulling off a band-aid. You just gotta go for it.
Put them in neutral territory and be ready with a towel or dust pan. This is where you have to be strong. There will be signs of dominance, and it will scare you if you are not ready for it. You have to let them work it out. Unless they become a rolling ball of fur when they fight, don't step in. There will be mounting and chasing and rumblestrutting. When we introduced Scooter to Scooby, all the dominance came from him. It was a very easy intro. When we introduced Emmet in December, it was a little harder. They practically ignored him, and fought with each other. At times, it started to get a little scary. Once drop of blood is all that was shed. Scooby learned that Scooter is still in charge, and he has no say so in anything. Now, all three live happily toghether. (Unless they are getting a treat of green apple and then Emmet is big ol' bully hording it all for himself.)
Good luck, and remember...there will be a little tension at first...but they will work it out.