Are Proto Man and Break Man two separate robots?
As far as I can tell, no. I realize people like to take the fact that he looks a little different in one stage in Mega Man 3 to mean that there are two different robots in that game. However, although it’s a nice idea, I have found no evidence in the games or other official sources to verify that this is indeed what Capcom intended. I figure if Capcom meant for there to be two separate robots, they would have made it clear by now. So until Capcom says otherwise, officially the answer is still no.