Any tank above 220 ilv worth their salt should not be losing aggro to you even without QS. I have every tank at 60 at 230 ilv+ and the only time I have to pay attention to threat is when I have a geared/skilled SMN doing 3-4k on pulls. Boss wise only my WAR can easily keep up with MNK/BLM dps in deliverance after my opener. I can see DRK/PLD losing aggro much easier on single targets if they sit in their dps stance.

TLDR: Your tanks are the equivalent to the dps I get in 230+ gear only doing 400 dps.