Yes what size is you cage?
You can easily make a bigger temporary cage really cheap. All you need is some card board (free) and cubes ($9-$15) or any type of wire that is higher than 12 in (if you also want to make the card board last even longer you can use lino tiles with self adhesive backs (Dollar Tree 3 for $1, 12inx12in tiles) and cut them to fit inside the cardboard and then stick them on). You make the cage the exact same way as you would with coroplast except you use card board. I just made a 2x4 cc cage out of card board, cubes, and lino tiles because I am getting a new piggy (this weekend) and I will be trying to introduce a third boar to a bonded pair which could take a while.
If space is the problem try rearraging furnature, or trying to fit a bigger cage in where ever you can (example you might need build longer rather than wider).
Other than making a bigger cage, I would suggest separating them by spliting the cage in half. You can use grids, plexi glass, or really anything where they can't break through as a divider.
My 2 boys have occasional squabbles but they have a large cage (CC 2x7) so they just sort it out, or stay out of each others way. Two boars in a small cage tend to squabble a lot because they are always in each others faces. Do you have two or more of everything (water bottle, huts, food dishes etc) in the cage? That sometimes helps. They won't squabble over who gets the water first or who gets to eat first or who gets the hut etc.
Oh also how long have they (your two boars) been housed together?