I'd be for it if not just for the sake of stopping one thing I've run into from time to time

Tank 1: I'm the tank.
Tank 2: NO I'm the tank!
Tank 1: NO!!! ME!!!
Tank 2: ME!!!

*fight starts after 10 minutes of tanks arguing*
*tanks proceed to try and out tank each other, mess up positions, dps and healer rotations and wipe the group*

Tanks 1 and 2: HEALERS FAULT!!!