Well let's face it not all training is equal and not all experience is equal. In a fight I'll take the guy with 100 street fights over someone with 5 years of tae kwon do training. But then I'd more than likely take someone with U.S. military training over any gang banger on the street. It doesn't just apply to fighting either. You can and do learn more from experience than you do from a classroom environment.
Basically though I have little respect for the ability of the average gang banger walking the street. They shoot a lot more than they hit and they run or duck a lot more than they stand up and fight. If they were really very good there'd be a lot more bodies on the street. Not necessarily a bad thing if they're shooting at each other IMO. Maybe we should sign em up for some hardcore training. On second thought, not such a good idea.
No one knows what they're gonna do in a fight. But from all I've seen I'll take my 25 years of shooting over some 1, 2 or 7 day class in a heartbeat.