I don't understand?

[echogame]

If you have a THM/BLM or WHM/CON in your group, ask them to sleep the ones you're not fighting, marking them with the 'don't touch' symbol. Should make everyone's life easier. Just realize the dravanians can't be slept. :X

...And let that DD who wants to tank some other mob die. He wanted to be tank, right?

[FGRogue]

If you have a THM/BLM or WHM/CON in your group, ask them to sleep the ones you're not fighting, marking them with the 'don't touch' symbol. Should make everyone's life easier. Just realize the dravanians can't be slept. :X

...And let that DD who wants to tank some other mob die. He wanted to be tank, right?

That's exactly what I do. I'm a BLM, I look at what enemies are around, which one the tank is targeting and cast Sleep on the rest. It's my job to support the tank and attack the single awake target. Once the others awake up, I Sleep them again.

As far as the others you've come across, forget them. They're just looking for something to complain about to cover up their own shortcomings from the sound of it.