I'd say used-to-wrestle-in-highschool guy is way more effective than untrained tough guy in a fight, and karateka are sometimes about on par with untrained people when it comes to moving on the ground, unless they've done some crosstraining or crappling, if early style vs style is any indication.
Old NHB fights had karateka/taekwondo guys and/or untrained toughmen frantically bicycling their legs from under mount, try to bench press the other guy off him, hold onto crappy headlocks like its a real attack, or try to kick or knee the guy from underneath while the opponent sits in mount or sidemount. These are the sorts of shenanigans that someone who even used to be a good wrestler would scoff at and easily defeat.
I've competed against a number of types of martial artists, and plain old wrestlers have given me the most trouble. I'd say that it takes a good karateka to stop a decent wrestler.
Of course, there's always the chance that the former wrestler gets KTFO'd on the way in with his rusty old takedown and lack of striking background.
1. Kyokushin trains with hard body shots but no head shots.
2. Kyokushin fighters consequently don't punch to the head in "real" fights. (bullshit)
3. Shukokai um...people train with light shots to the head and body.
4. Shukokai people consequently _________________ in "real" fights.
My guess is "pull punches," which was always my nightmare when I did point krotty back in the day. It turns out I was right, too, because when I got to a knockdown karate school I spent a long time under-committing to techniques, failing to drive with my punches, and worst of all, stopping after I got in a good shot. After all, the ref was about to call stop, right?
I also laugh in the face of your whole "instinct" argument. Who cares if your instinct in a fight is to throw a hard right? If all that matters is instinct nobody should be training at all and this forum should shut right down. Apparently we can train to respond EFFECTIVELY rather than INSTINCTIVELY to stimuli.
Getting all holier-than-thou, passive aggressive, and then rage quitting.
GET YOUR OWN TECHNIQUES!