
We have two males with nearly 4 years between them and they get on fine most of the time but have had a couple of punchups in their lifetime (youngest is 7) Mostly though they get ratty with eachother when a bitch is in season and must admit normally it's by one of us humans being careless!
However my grandparents had two males who got along fine and they brought a 3rd one in, admitidly at 8 mths old. After a couple of months the new dogs started challenging the eldest and "top dog" and they still tot his day have to be seperated. The two middle one got on fine with both for awhile but then started challenging teh eldest (poor turk was getting picked on! :( ) The two youngest stil getting on. then it turned and all of a sudden the two youngest strated not to get along. All 3 had to be seperated at ALL times. :( With this we will not bring in a 3rd male.
You are more likly to be able to get to males get along but make sure you bring in the pup at 8 weeks. I think my grandparents problem was bringing in a 8 mth old that was getting to his bloshy stage. If he had been 8 weeks he might have learnt that he was not going to be top dog untill turk backed down!
Also how is your current male with other male dogs? Does he get on fine? OUt of the dogs who is top? If one of the bitches is top then there will be less challenging. OUr boys never used to fight while Emmi was top dog. the first fight strated soon after we lost her when the top dog role became avalible. This is just what I think it's how it started, but 99% of the time we live with harmony and peace. the boys sleep curled up togther and I have photographic evidence!