New Aggression in male rat

So recently I got my third rat and introduced him to my other two boys. Introductions went great, some dominance scuffs but that went away fairly quickly. After I moved them all into the same cage however one of my resident rats became very aggressive to the other two, including his already cage mate. I have since separated him from the group and he is living on his own, as of a couple of days.

My question is, if I neutered him to calm his aggression and reintroduced him to the group would that be okay? Or for male rats do they all need to be neutered. The reason I say just him is because my other two babies are fairly chill.

Any help or advice would be appreciated!