if you got 3 or 4 guys on you I don't care what you specialize in grappling/stand up/clinch your toast. You cannot fight that many people I don't care what secret tech. some buddist master taught you, your going down and there is nothing you can do about it. The best you can do is run away before they get you cornered. Hopefully you are faster.

best defense in that sit. would be a gun. Equalize things out a bit.