we have two males with 8 weeks difference in age, no real problem. We have had to train them apart as together they did ignor us when really tiny but at 9 months and 7 months still no problem and they play with each other wen left alone and kennelled they are never alone a dog. So unlike most here I would say fine. To qualify one thing though the dominant older dog is a cocker 9 month Whistler the younge dog is Jake a border collie, but still subserviant to Whistler!!
Viv