No support.
This isn't how tank works on OSRS. Verzik chooses a tank at random from the alive players in the raid party just as she does currently on Alora.
It's also incredibly easy to swap tanks if someone is that adamant on refusing to learn the mechanic. Just stay out of Verzik's melee distance for two full attack styles and Verzik will select a new tank. At the end of the day, it's something people need to learn if they want to do ToB and if they never have to tank, they'll never learn.