What style or exercises in wpierdol do Russians recommend?

Street fighting is becoming very important for day to day living, thanks to our esteemed guests from warzones and 3rd world countries. Unfortunately, the level of wpierdol is very low in Germany (all manuals and clubs got banned after WW2 and we are left with what the Americans deem "good enough" for us, ie. bad boxing, non-existant wrestling and assorted kindergarten-hippie Asian arts) and training in fighting is extremely unpopular. Not so with our new guests from all over the world - they have trained in countries where knife fighting and boxing/wrestling seems to be extremely popular or at least they are very good at it and rather ruthless.

As expected, this creates a bit of a power slope. So, because I don't want to sully myself with Muslim fighting tactics, I'm asking you Russians because if nothing else, you're at least Christians (I could ask Poland because they are even Catholic like me, but they hate me because we played a rough game with Poland 70 years ago): How to become really good at fighting without any rules, ie. street fighting.

Additional info: I have seen good athletes getting really badly beaten up, so I'm not sure combat sports is the right answer, but then again, as I said, the level in Germany is really low.

Picture: Germans are improvising with lifting weights and steroids, the results are so-so at best.