Aggression 3 male Guinea Pigs now seperated. Can they be reintegrated?

Hi there! I wrote a post recently about seperating my 3 male GPs (around 9 month old). The largest one of the three definitely asserted dominance around 2 months ago and I began to notice lots of chasing and biting. The medium sized GP is now missing a large amount of his back fur and is covered in bite marks. I ordered the C&C XL cage and I hoped with more space the behavior would get better. I also got the divider in case I needed to seperate them. I was also worried about the smaller of the three being bullied away from their food as they are significantly smaller than the boss pig. The chasing and biting seemed to get worse once I put them in the new cage (perhaps he was trying to claim territory in the new environment), but the final straw in my decision to put up the divider was when I observed boss pig repeatedly mounting my littlest one who is blind/deaf. Boss pig is over double the size of little one and because he doesn't have his sight it is hard for him to escape from under and he ends up discombobulated and winds up on his side or flipping over. I am worried boss pig will suffocate the little one or injure him in some way. So now the two smaller pigs are on one side of the wall and boss pig is alone on the other. I have two main questions. 1. The way I have the divider currently they can still see each other. Is this ok or is it better for them to not be able to see each other? 2. Is there any time in which reintegration would be possible? For example if I can plump up the smaller ones so that they are on an even playing field size wise would it be safer for them to be together again? When they get older and out of puberty? Should I consider rescuing a fourth to be a companion to boss pig? I really want to do what is best for all of them, but I am terrified to walk in the room one day and see that boss pig has injured or worse, killed one of his brothers. I also don't want him to become depressed from being alone. I put a plush hidey and other soft things for him to snuggle with. I can say the smaller guys seem much more relaxed now. My blind/deaf GP never came out of his hidey before and now I see him out of it all the time and he is having an easier time eating and drinking. Thank you taking the time to read all of this!