The video you posted shows some well trained athletes.
I have in the past fought guys on this level in full contact MMA‘s competitions and in self defense situations.
I am not going to post any more methods on this website.
How ever if you want to exchange ideas via an email address then we could discuss it further that is entirely up to you.
I have read what other people have written and all I can suggest is in order to prove their comments they might want to find some one of that level, ask to sparr or fight or even just train with them and see if what they are saying does work. Or perhaps not as the case might be.
This practice does still exist in some South American countries (and indeed in some other countries with gypsies,) where large groups meet, after a carnival, fight in the streets, don’t get arrested, and work out what works and what doesn’t, or where they went wrong in training. The methods that do work means the guy is still standing.
It also use to happen in Okinawa where they would also meet then fight to see who had the correct/better fighting method. Unfortuntley in this day and age it rarely happens apart from MMA’s which are to a degree controlled.
So we have the theoretical squabbling and deviations of reality.