So I assume that they are four casters and a tank, you engage some mobs with the tank and the casters blast away the mobs. But then the unthinkable happens, the casters are feared in every direction or the tank is kicked behind the casters. Or some other earth shattering problem.

Typically i have all the casters follow my warlock or my healer (sometimes one and then the other if its a major fear bomb issue) and then I have the healer or warlock IWT with my tank and then stop moving. This brings everyone back into turret of doom position.

This often happens if your casters are following your tanking during combat (eg, your poor casters are getting cleaved, are actually following your tank when he is feared or kicked and so forth) ... you need to 'drop follow' before combat if this is the case.