In my humble opinion (as an old bloke, with a limited skill-set) being surrounded by a circle of pads which "attack" you one at a time, is a bit lame. However, having five of your mates beat the living daylights out of you is a wee bit over the top.
There is the excercise in which you stack up your oppos, trying to get them in a line. This works well on a big mat with two (friendly) nasties attacking, but I'm not convinced it has any real merit.
I do like the one where you start flailing your fists in cirles, turning around and swearing like Jet Li on acid. It does make the pad holders move backwards and fear for their safety.
Lets face it, for most of us fighting one person is bad enough, two is a nightmare and five is right up s**t creek without a paddle. So how can we train for that?
I think strong mindset is key to surviving in most confrontations, not stopping, not giving up & getting back up when you are knocked down.
There are loads of great mindset drills around, have fun with them (but keep a bucket handy for when you overdo it).