Does no one else use "Target of target"?

[Tinoris]

not to target the enemy the tank wants me to kill, i use the enemy unit frames for that

i actually don't kill what the tank wants me to kill, i kill whatever is taking the most damage. and when i tank, i make sure whatever is taking the most damage is attacking me.

That's seems pretty backwards to me. As a tank, you are the party leader, and hate management should be proactive, not reactive as you describe. If you are a good tank, no one should take aggro from you. Marking is more efficent, plain and simple. And way easier for tanks that are out geared by DPS. Oh, and a bunch of other reasons...see some of the other comments here.