i think you mean aggression, not fight. a smaller dog can be as aggressive as eff but he's not going to have the fight of a larger dog. by fight, i mean the ability of a dog to negatively impact another dog's morale through the application of force. just the other day i had a toy pit bull that was super aggressive, so i put him up against a friend's standard staffordshire. needless to say, the toy spent his aggression on the larger dog, but to no avail, and the staffy was able to apply his superior fight to destroy the toy pb's morale. i've seen that same scenario over and over again, so i remain convinced that there is indeed a very strong correlation between a dog's size and his fight.
Ah, I read ya. We're on the same page.

Hey by the way, I've got this mutt you may be interested in. He's got a bit of flandoodle in him, so we just call him a "fla-daggy." He's fairly scrappy, but he got into a little scrum with a horny toad last weekend in the backyard, and he hasn't bit quite the same ever since. He's done alright in the past (4-1), but I was just going to put him down. He's ugly as sin and half Fake Sugar Dick (WARNING, NOT THE REAL SUGAR DICK!). My sister's kids don't even want anything to do with him. But anyway, if you'd like to let one of your champions tune up on him a bit, just let me know.