Should be able to as long as no fighting especially if not in the company of ladies..... if they are going to be with the ladies try to stick with the 7-10 gals per guy or more. And be sure that they each have plenty of space to get away from each other, seperate feeders, waterers.... as they will likely each take their gals to their territory (respecting-hopefully-the others territor)!
I was able to keep my boys together with 12 hens for most of the first year but as spring has sprung, so has their need to dominate - and fight. I am able to let them free-range together but they have to be separated now when they are confined (at night).