Not necessarily, it really depends on the circumstances, a man who is a bodybuilder vs a crippled elderly man with a pace maker it may be justified self defense.
A lot of factors come into play, personally no matter what if you fight there is a chance of trial even no weapons, but we are talking about reality here, and your opponent may or may not intentionally try to kill you but you have no idea knowing that lots of people get killed by slams and weapons why risk it, for me I have to make it home don't care what I have to do to be able to do that. So about reality are you prepare to stab, bite hit a guy with a brick to get home because he might be.