These are needed for the Ring of the Shissar, key to the Emporer's chamber, but it seems the pieces they drop are beyond rare.
Just after the server reset today I took a group down to start farming pieces for the key. We killed 7 named taskmasters and the Warden, but only a single 'Taskmaster's Pouch' dropped. 6 out of 7 times today the body just poofed with nothing on it. Previous attempts at getting these pieces gave similar results.
It just seems like these named mobs are very hard hitting and challenging for one group, something should drop after killing these guys. Perhaps look into having a piece of the key (random) drop each time one is killed. Or since these guys have a rather long respawn, up their repop rate to make the quest more attainable.
Let me know if I'm way off base with this post, obviously I'm a little tweeked at getting stiffed by the drops these guys have again...
Aarcore