[dethstar]

No martial art is useful against multiple opponents, despite what they may claim.

Yeah, someone's friend is going to kick you. But why wouldn't they kick you if you're standing and not facing them?

I wouldn't say that's a disadvantage of BJJ but rather one of facing multiple opponents. Like facing someone who has a gun. You're at disadvantage no matter how much knowledge you have.

[tiatia]

My knowledge is not enough. But I knew people (now very very old) that were able to pull this off.

They actually trained under Masutatsu Oyama with can be seen in some ways as precursor of MMA.

I have also seen Boxers pulling this off to be fair. But any ground martial arts like is not suited to this.