Sorry to hear your boys aren't happy with each other.... It's difficult when pet stores and private breeders/individuals will sell any selection of piggies to anyone without thought for compatibility. You wouldn't pick your husband or wife out of a room full of people on first sight and then expect to live happily ever after in a bedsit forever so people shouldn't expect piggies to effectively do the same

But even with bonded pairs, sometimes it all goes wrong especially with lively pairs of boys when they get to their hormonal teenage years and suddenly their best friend isn't so friendly anymore..... Been there, done that!
Wiebke has given you the same advice I would have given... It's always good to try dating at a rescue because then your boys can find a buddy they get on well with, be that another male or a lady friend after they have been neutered. I've been boar dating 4 times now after bereavements and fall outs and it's a great way to let your piggy find a friend they love. Like Wiebke says, if you want to go down the route f neutering then make sure you use a good, experienced vet to reduce the risk of complications and make sure they have 6 weeks alone to make sure they are safe before introducing them to a female. Accidents can still happen at around 5 weeks post neuter so it's worth waiting! BARC is a great rescue, I had a lovely boar friend for one of my boys from there and a bit further afield, Milhaven Rescue is also excellent and I've been dating there too. It's worth waiting to find the right piggy. Bear in mind that it's all about compatible personalities so don't worry if the first piggy you try isn't 'the one', be patient and try again, the right pig will be out there somewhere.....
Keeping them side by side is a good solution while you decide what your options are. Sometimes they get on better with a divider, a case of can't live with you, can't live without you.