little rumble bunny

We have a buck(named Foofoo) who has been challenged by his offspring before. A little bunny boxing. They usually box and run for a few days until the submit to pop and everything is fine. We have one though who is about 7 mo.s old now(named Bolt). He's always been a little wild. I've always said since he was a kit, that he thinks he's a wild bunny. Everything seemed fine though, until about a month ago, when the fight was on! They had plenty of room, so we watched at first but neither one would give up. Bolt seemed to be more the aggressor and pops was getting beat up, so enough was enough. AND now all the bucks were fighting each other! We had to separate all 5 of them. So we went from all 5 of them living in a colony to 4 in a cage and one at a time in the pin to exercise. Obviously I'm not liking this new situation. Even the two brothers who were always together, bffs, started going at it. I realize we should probably get him fixed. He is not a cuddle bunny like his dad happens to be, but he's just a fun guy to have around(until he stared beating everyone up). I have just always loved this guy, since he was a kit, crawling out of the nest and trying to brake free lol. So part of me doesn't want to fix him, but I should assume it change his personality 100% and I have to think of the whole group here. I don't want to find him a new home, obviously because of my affection for him and I'm afraid he's too wild for the average rabbit pet owner and wouldn't want him to end up being locked up all the time.
Also, I want the rest of them to get along again. I've never gotten into the whole "how to bond your rabbits" thing because mine are not house rabbits and since most have grown up together and all are used to other rabbits, we haven't had a problem. I don't need Foofoo and Bolt to be best friends, I don't even need them all to pair up(one I'm trying to adopt out right now). I just need to them to be happy and get along. Any tips on at lest getting the rest of them to get along again in a group setting? Keeping them apart is probably only making it worse, getting them used to being alone. We've tried just putting them back in the pin together but the rumbles have broken back out. Any Ideas? Other tank just fix them all please? Not able to get them all fixed at once and that's no guarantee.

Male rabbits fight. Its a fact of life.
I own an acre and see wild male rabbits fighting all the time.

If an acre isn't big enough for 2 male rabbits, how will 5 ever get along in a smaller space?

I would keep separated and either accept that fact, or rehome them.
I'm afraid some severe damage could be done if you continue to put them together.

by 12-14 weeks old buck will fight. Separate them, butcher them or get rid of them before that. I sex my kits and put the bucks in one grow out, the does in another. The buck have to go as soon as they are at weight (8 to 10 weeks) the does can wait until the following week or even two weeks if life is busy and I can't get to them.

If you are going to have a PET buck, then you have ONE or, keep the separate at all times. Neutering may work on them after they start fighting but, may not. If it had been done before they were old enough to fight, then you might have had a better chance of them not fighting.

Bucks fight, that's how rabbits are.

Most of us don't try to get bucks to get along. It's hard enough to maintain peace with just DOES.

I think their aggression is natural and it would have been set off eventually, even if you hadn't had Bolt starting trouble.

Mature bucks can kill each other. I saw one with his nose almost completely bitten off once.
I have heard of people having TWO mature bucks getting along in a colony, but it's not something you can even EXPECT to have happen.