Hi!
A hutch is unfortunately too small to try and see whether your quintet of teenage boys can make it; it is about the smallest group size that has a chance. But you would need about 1 square metre per boar
minimum to allow them to get away from the others and you need to have exactly the right mix of not too dominant teenage personalities.
If I were you, I would observe your boys to see which ones would pair up best to have two stable pairs but considering that you are currently in the highest tier, you may want to see whether you can hang onto a trio for the time being as there are no good rescues in your immediate area. The RSPCA only offers adoption of neutered boars or cross gender bonding with neutered boars as part of their policy of preventing more unplanned pregnancies.
You can then (depending on how things go) either pair up the odd one out by rescue dating or contact a good welfare standard rescue as to whether they can take your extra boy in and ensure him a safe home with a suitable companion he clicks with.
I would report the pet shop to your local council over trading standards. That is more than just a little accidental mis-sexing!
Glad that you have at least got all the same gender so you are not ending up in our pregnancy support section over a flood of unplanned babies.
Are your piggies outside and how are your winter and summer protections? Guinea pigs are no hardy and should be safe from wind, rain and cold. They should be ideally treated like you would treat tender plants. Please be aware that boar pairs still need a minimum of 2x5 ft space on one floor and an extra hut with two exits to allow them to get away from each other.
Cold Weather Care For Guinea Pigs
Hot Weather Management, Heat Strokes and Fly Strike
Here is our rescue locator with our carefully vetted recommended good welfare standard rescues:
Rescue Locator
Please note that anybody in this country can call themselves a rescue or a breeder without licensing and supervision. The results can be accordingly; you have that already found out in terms of pet shop quality. We can only guarantee for the listed rescues; they all have a mandatory quarantine, full vet care and a mandatory pregnancy watch for any incoming sows past weaning. They will only rehome properly sexed and stably bonded piggies, and - provided that they can do this safely in the current fluid pandemic conditions - offer dating for single boars (full and neutered).
Please take the time to read all the guide links. Think things through and do your research. We are here to answer any questions you have connected with this problem in this ongoing thread, so we can keep all information together and if necessary refresh our memory of the background and the conditions you are currently placed under; which will impact on your options.
PS: Could you you please use your general area as your location in your account details which make it appear with every post that you make. We are all volunteers doing this unpaid in our own free time and would rather not have to spend that time on googling so we can help with more local tips without having to ask - the general area is enough for us to tailor any recommendations.
It is also for your own personal protection that you are very careful with giving out any too specific information about yourself. Thank you!