You are lucky! It sounds like you have a nice little family.
Intact males who've been raised together, without a female, quite often get along great. When I got Washi and Kioko, brothers who'd been together their whole lives, they were intact and five years old. I got them neutered because of the smell, but mainly because I got them to introduce to my five-year-old neutered male, Shikoni. If they'd been left intact, there would have been trouble!