I run 2 entire males together, and both on their own with a bitch, as and when.
I have never had any problems. Mine are all kept as a pack, they know I am at the top of the pack and what i say goes 99% of the time. I always feed according to the pack and same with working, the top dog always has first slip then they can run as a pair. With mine its all about how i am around them, they pick up on everything. I do have a pup coming on who will challenge for pack leader, but he will not get past me!!