I'd go with golota, he trained with a heavy bag that had trunks on it lol, had the direction to end fights on ball shots.
Bernard Hopkins, liked to graze low at times especially when the ref was on the other side blinded from the action.
Then, Andre Ward: he buttered up his opponents like Kovalev with ball punches that made him keel over in pain and then he went for the head when their hands were down protecting their balls,
Siri most recently. Treated Lomas balls like a speedbag that fight.
Funny you mention that fight. That fight popped up in my feed yesterday. Some guys were rescoring the fight, so I rewatched some it.
They started off okay, and then his body shots got lower and lower as the fight went on, and then toward the end, Siri was punching Loma's kneecaps lol Shit was so ridiculous. Yeah, half of those shots were on the cup. I wonder what groin guard Loma was using. Should be industry standard.
Salido was pretty sneaky for most of the fight. He knew were the referee was all the time, for the most part. If you want to cheat, that fight can be a blue print for boxers.
Since I'm still asking questions lol, may as well ask who was the most flagrant headbutter?
Evander Holyfield comes to mind, it's like you had to fight for the spot aka head placement as Evander wouldn't budge back or lose ground by taking a step back aka he knew where to put his head. In the Toney fight Jay nady kept telling Evander to watch his head, and thankfully James Toney leans back a lot and doesn't lead with his own head.