Certainly one can sue anyone they want, but the trick is getting blood from a turnip. If the goal is to bankrupt forever someone, and you the person suing have the money you can sue, get your judgement, and garnish their wages until the judgement is paid. Think OJ Simpson. Anytime he gets money, it goes to repay the victims. But unless that is your goal, (as it was for the victims family's in OJ's case) it is not a realistic endeavor.
But to your question, yes, he could sue them all.