you can sue in federal court if the people involved are from different states and more than 75,000 is at issue in addition to bringing federal claims.
If one wished to really hogtie Crystal and her gang of low-rolling legal talent, he'd see to it that one or more of the players started a state court action in their home state and county, for slander, against Crystal and anyone else who has slandered them, or allegedly slandered them.
In the cause of action slander, the injury to the victim/plaintiff in his home area is an important factor. Of course, a national figure would have the whole nation as his home area, but in the case of these players, most will return to their homes to make a life.
By initiating state court actions, and by initiating several in several states, by different players, you could force Crystal and her team to either fold or respond. They don't have the resources to respond in several jurisdictions, and if they seek to move it into federal courts, all the better.
I would guess her team would either fold on civil issues early, or they'd put her in a bankruptcy, in hopes of trying the issues one time in bankruptcy court.
Any way you slice it, the best defense is a good offense, and if you make them commit their resources to responding to your demands, you keep them busy from causing you other trouble.
I'd be making all these losers backing her pony up serious litigation costs and time.