My first two boas had a fight , it was scary because it was the smaller brother (the mild mannered janitor turned Hong Kong Phooey ) got his teeth right into his brothers back.
I'd say go back to basics.
Wash them, nice strongly scented shampoo (Gorgeous Guineas or nip down to your local petstore and get something scented for rodents)
A bath gives them the rage at you hopefully it will take their minds off each other.
Clean their cage Pig Neutral, scrub it with white vinegar.
Bigger is better with pigs, always have two doors in their housie so they cannot trap each other.
Two bowls , keep food spaced apart.
When you rebond , a neutral space (we used a paddling pool) , huge pile of food and grab a towel. You might literally need to 'throw the towel in' if they fight, don't get your hands in the way of warring guineas.
It might be (as with my boar and the two sows we got 2 years ago) that they cannot live together.
I bonded a boar+ a piglet
The piglet (grown) with 2 sows
The 2 sows with our present boar
I tried to bond our newest sows with the trio (failed) then the sows with our boar (after his wives died) failed.
The aggressor is my piggie , who is a sweet as a button but attacks our boar.
Sometimes for their own safety you have to accept , but I'd say give it a go to rebond but if it gets spiteful, wade in with a towel.
Good Luck