There are ways to deal with multiple opponents. These scenarios should be trained often. It seems that more and more confrontations are going down this way these days.

My training:

1. if you can run, run.
2. if you have to fight, fight
3. don't choose your opponent, wait
4. as soon as someone steps into your space, take 'em out
5. if at any time you can run, run
6. deal with opponents as they arrive
7. always stay on the flanks

Sounds like a lot but it makes sense.

I recently assisted a black belt grading where about 6 of us senior students attacked the guy grading. He killed us. And we were really going at him. Different from the street, but no less impressive.