You will have to prioritize your shots. As others have said, take out the most threatening first (the guns, the contact weapons, size of individual). Realistically, after shooting once or twice, they should all be running and at that point the threat of death or great bodily harm would be gone and you are no longer authorized to use deadly force. I think I read somewhere that the average number of shots fired in a confrontation is between 1.5 and 3.0 – From a legal standpoint, it’s always best for you to remain within the averages. If the last person standing is unarmed, you cannot shoot because disparity of force (number of assailants) no longer exists, unless you are female or the other guy is A LOT LARGER than you, you have become disabled or its known to you that the last standing man has training in the “killing arts” (black belt, Navy Seal, Ranger etc…)
My $.02