That's why I've never liked RP combat, the human being is bad to recognize his defeat, it is designed to survive, to try to the end and few have the necessary hindsight to be sufficiently impartial with themselves. It takes an unbiased system to make it work, usually based on math or a system of rules of the game common to all.
I strongly recommend that you write only to tell a story, create characters, interesting situations, instead of trying to arbitrate any fight.
Moreover, being OP doesnt necessarily make a bad player. Take the example of One Punch Man, it is the proof that one can write a good story despite the main character who surpasses everyone. The same faction that assumes its OP side and plays it parodically could be funny. One can imagine, a pretentious and obese lord, who throws money through the windows and who doesnt hesitate to sacrifice lives and ships that he has in quantity. And who wouldnt be a threat to anyone so much it is scuttled by itself by its own incompetence.
"Die, inferior beings, I am so strong and intelligent!"
"My lord, the crew of Human Shield 46 is in a strike."
"Humph ... Bomb these unionists."
For example.