Yes, this analysis assumes the objective was to kill your enemy. Another view would be that generals that won battles with the fewest casualties on either side (or civilian) would be the most effective.
Otherwise, a general who was willing to nuke the other side might "win" a lot of battles, especially against a "replacement" who is morally opposed to civilian casualties.
You can also win the battle and lose the war. Are generals that overcommit to win a battle really good generals?
On this note, Otto von Bismark might be one of the most accomplished heads of state of all time, what he managed was pretty extraordinary, but at the same time he was swimming with the historical tide, so it somewhat magnifies his accomplishments "great man" style.
I wonder how true this is of many generals as well.
Otherwise, a general who was willing to nuke the other side might "win" a lot of battles, especially against a "replacement" who is morally opposed to civilian casualties.
You can also win the battle and lose the war. Are generals that overcommit to win a battle really good generals?