Indeed up to a point
A large street fighter can dominate a small martial arts guy
I’m talking large discrepancy in size
My best friend was ishiynru karate black belt but only five four 130 pounds
He knew a six five 240 pound fighter or tight end was a tall order
But yes generally speaking training is everything especially boxing since fights start that way
Then ground game is paramount
Where wrestlers star
I saw a 145 lb Golden Glove champ ( yes he owned the diamond encrusted golden gloves) take out a 250 lb bouncer with three punches. He did a lot of damage to the guy who, it turns out, was getting married the next day.
He knew a six five 240 pound fighter or tight end was a tall order
When that is the case you have to do enough damage to the assailant in the initial contact to disable him or impart enough pain to cause him to decide it's over. Taking out a knee works nicely. As a bonus, that SOB will remember you every time he stands or walks as long as he lives.