What height and weight would make you a formidable opponent against anyone of any size?

I know this is somewhat of an abstract question, but I see arguments online all the time about how 5’4 MMA fighters can beat 260llbs bodybuilders and vice versa.

Assuming you are a well trained mixed martial artist going up against a very large opponent who is between 6’5-7 feet, and up to 330llbs, with minimal training. What is the minimum height and weight you would have to be to be able to defeat most anyone of that size in a fight at least 70% of the time?

Again, assuming the large opponent has little to no training.