I don't think Bobby Bacala was a murderous sociopath. He has one kill that we know of, and it made him sick. Of course he shot a rapper in the ass but that was at his own request.
Tony, Silvio and Paulie certainly were sociopaths. You have to be on that level. And look how long Bobby lasted on the administration. Cared more about his toy trains that the mob life, and he died with them. I dont' think Bobby fit the sociopath profile.