For keeping the males from fighting:
a) they were probably raised together, which helps a bit.
b) it doesn't matter if they just ruffle their feathers and jump around and do not hurt each other. Many roosters can settle their issues this way, without any actual injuries. (Might have a few bloody combs, but those heal fast enough the person can ignore them.)
c) if one or more are causing actual injuries, cull those birds
d) in some conditions, more chickens will actually fight less. I think it's because no two can get a good fight going in crowded conditions.
Multiple males per pen is normal when breeding chickens on a commercial scale, and most breeds will do just fine that way. They have been selected for a long time to NOT kill each other in those conditions.
I don't know for sure about the size of the pen, especially because you were not able to actually measure it. But chickens will often do just fine with 4 square feet per chicken. No run, just that much space. By "doing fine," I mean they stay alive and apparently healthy, they lay eggs, and they do not peck each other badly enough to affect production.
(I have no experience with this breeder, just saying it sounds like the conditions I would expect for breeding flocks that are well cared for but not pampered pets.)