If the fight gets to the ground, wouldn't some knowledge of BJJ be crucial?BJJ is good but wouldn't recommend it on the streets were rules are pretty much non-existent
Can't do BJJ on concrete or similar and you clearly can't use it if you're against multiple people
Judo is a lot more practical and ends badly for the other guy especially if you're on concrete
I'd recommend Muay Thai/Boxing although it's much harder to find a gym that is primarily does Muay Thai in the West
I've seen a lot of street fight vids and a number of them end real bad when one guy knows what he's doing on the ground