See i go the other way with that theory. If you cant be successful sparring with rules how are you going to fair in a fight without them. If you are successful with rules then you will be more successful when the rules are not holding you back.
Now that is not a reason to abandon survival or street methods but it is a reason to train in a system that is at the very least starts with good fighting basics.
Ok SD on resisting opponents is sport as i imagine you are describing it. Very few people when they say SD. Are suggesting that you go out and get practice mugged. So it becomes training in a gym under a rule set.
wrestling is one of the oldest martial arts. Sumo pretty much predates most Japanese systems. So i would suggest sort fighting is as old as any system and possibly older.
But yes mma does not cover everything required to do be well rounded in self defence. But here i advice people seek out quality guys. So if you want to stay out of jail. Legal advice from a qualified lawyer who has gone though it would be better than the advice from your self defence coach.
Specifically regarding knife defence is tricky. Because there is so much theory and misinformation. And so little real data.
For the first part easily. I cant step in the cage. Reason being, last time I heard of and did this with my MMA friends, I instinctively tried to do the SD techs I've drilled into my head. I.E. When they try to clinch, I headbutt, and stomp down on the knee. shin, and foot. After a bit of adrenaline gets in my system, when theyd shoot, the first thing Id try to do after a sprawl was a downward punch or elbow to the back of the head. After the first couple times, I was able to catch myself but it was really affecting my ability to spar under their ruleset.
When we split it up, which is how most gyms actually train for those who dont know, it wasn't
that bad. Mostly with grappling, because after I hurt my shoulder the only grappling and rolling I do is SD oriented. Instead of worrying about scoring and protecting myself from being scored on, Im drilling sprawling, getting back to a neutral position, and never stopped attack with something no matter what. With striking, I work with 3 different rulesets so I dont get so used to one that it becomes how I fight.
I cant box anymore either, because Ive put so much time trying to get all 4 limbs working as one that I kick, which is obviously a no-no.
Training for specific set of rules as your focus is a restriction.
Second, your implication that for a school to have good fighting basics must be sport oriented is very flawed. The military doesnt teach sport fighting, yet I'd doubt your typical Sport fighter could beat up a Marine.
Third, not sure what youre going for. Theres little difference between a drunk guy in the parking lot swinging at you and someone else twice as large as you coming for blood in a training hall.
Fourth, yes but cavemen were defending themsels from other cavemen long before Greco-Roman wrestling. Before sport or style. Animals fend off predators in the wild, are they not really fighting for their life because they dont train in sport?
Fifth, you basically just proved my point. Sport training isnt the "best" way to go about learning to defend yourself. It cant be since you have to add SD training to it. Your argument of "Sport fighting is the best method" is essentially the same as saying style X is better than style y because we do this and you do not. Or, you do it a different way.
Yes, theres a lot of theories. But there are also many simple concepts to understand techs to learn so that you at least have
some knowledge or idea of how to respond. But i've never seen it in an MMA gym. I have no doubt, gyms with a separate SD program will have it. But I;ve never seen it as part of a Sport curriculum under any style. Aside from the minute possibility you need it in SD, you probably will never use or see it in a tournament, so why should a sports school teach it?
Another problem, I did Bullpin sparring and 2 v 1 kickboxing with my MMA friends. It didnt end well. They spent so long training to focus on one opponent and blocking out the rest, because in the ring they'll never fight 2. They had a hard time balancing it out. Whereas in 5 years of SD focused non sport style, my heads on a swivel. WE teach to always be aware and take note of everyone and everything in any given place, the mantra "have a way to kill everyone you see." They hadn't even heard that from their coaches.
Obviously, regardless of your style, cross training and exposure are the 2 most important things. But the idea that Sport Training is a necessity is a fallacy.