It would surprise me if Peter's body count were not prioportionately much lower, not because Peter was a nice guy, but because the technologies available for mass oand asseembly line killing did not exist.
jks --- People have been putting cities to the sword for millennia. All you need to destroy Carthage is swords, javelins and salt.
Stalin is reputed to have herded people onto boats and sunk them. That's pretty low-tech.