What if the trios are litter mates would that not change things. I am getting my piggies from a breeder
Hi and welcome!
Great that you are doing your research beforehand.
It is unfortunately a myth that brothers don't fall out; it all depends on their individual personality and the ideal balance of them if they want to make it together. That is about as often as people end up with three single boars. The majority of cases (and teenage boar trio problems are one of the issues we are most often contacted over) end up with either one dominant boar terrorising the other two, two boys ganging up on the third or two boys getting into a dominance dispute with the third trying to hold the peace.
Please take the time to read these two guides here. You will hopefully find them really helpful.
A Comprehensive Guide to Guinea Pig Boars
Boars: Teenage, Bullying, Fighting, Fall-outs And What Next?
Cage Size Guide
Please also be aware that breeder and pet shop piggies don't usually have had much in the way of friendly human interaction and that they are not instant cuddly pets; they are a prey animal species very much in their own right.
Children And Guinea Pigs - A Guide For Parents
Boars, sows or mixed pairs; babies or adults?
Arrival in a home from the perspective of pet shop guinea pigs
Please also be aware that for sale piggies (shop or breeder) can come with some extra problems:
What to check and look out for in new guinea pigs (vet checks, sexing, parasites&illness)
If you want to have a problem-free start, please consider adopting a bonded trio of sows or two sows and a neutered boar from a good standard rescue with mandatory quarantine/vet care, pregnancy watch, proper sexing and respect for character compatibility in their pairing up. They will also only rehome piggies that are used to human interaction to new owners. You can neatly avoid all the usual pitfalls that await the unwary that way and get a lot of extra service and support throughout the whole life of your adopted piggies!
Recommended Guinea Pig Rescues
Please note that younger children should at all times be supervised when interacting/handling or carrying guinea pigs and that any piggies will be in effect your own to look after and care for in the longer term once most children have lost interest.
This guide here looks in detail at all the practical aspects and challenges that long term pet ownership can bring with it. You may find it very helpful to take into consideration:
Children And Guinea Pigs - A Guide For Parents
Here are our full guide collections for Wannabe guinea pig owners and for new owners (the second specifically addresses all the practical aspects that new owners grapple with and helps them to learn to settle in, understand behaviour and learn what is normal and what not):
Are Guinea Pigs For Me? - A Guide
Getting Started - New Owners' Most Helpful Guides