JerryM, if they had guns, probably shooting at you, and possibly hitting you and/or the one you grabbed.
If they had knives, possibly slicing and stabbing at you, and possibly hitting you and/or the one you grabbed.
If they had no weapons, probably punching, kicking, and grabbing at you, and... you get the idea.
In martial arts training, we call this "randori," or multiple-attacker drill. Depending on the skill level of the monkey in the middle, the attackers may be constrained to simple punches, or punches and kicks, or grabs, or combinations of the above. Sometimes the attackers are given "shinai," the split rattan swords used in kendo.
One learns a few things very quickly.
1) Do not stay in the middle. It is a bad, bad place to be.
2) Try to get them in each other's way, by aggressively moving to the outside of the group.
3) Stick with simple attacks and counters; focus on not getting grabbed or hit, primarily by moving.
4) Tying up for any amount of time with any one of them tends to get you hit in the head with annoying frequency.
5) Depending on level of contact, simple could also be reasonably brutal. Iriminage techniques tend to work very well, as do certain weight-dropping techniques.
6) Attempts to control one, to use as a shield or a projectile against the others, can work - but if they don't work on first try, don't continue that attempt, get to the outside. Another opportunity may present, or it may not, but if you aren't getting damaged, who cares?
7) Hesitation = getting hit. If they are armed, hesitation = getting hit by very bad things.
You might be surprised, though, how likely the group is to injure or strike each other in such a scenario.
Of course, if you aren't both good and lucky, they are also likely to injure or strike you.