Try interact with target for looting. It is also good for quests -

  • To enable these features, go to your Blizzard Mouse Options {ESC > Interface > Game {Not Addons} > Mouse} and enable Click-to-Move on your slaves {Enabling click-to-move on the master is not advisable...nothing is more annoying than trying to click a mob and running off into the distance}.
  • Now go to Key Bindings again {ESC > Key Bindings} and look for the Targeting Functions section. Near the bottom of that section, you will find Interact With Target. Set this for everyone. I use ] for my team.
  • Finally, create a macro on all your slaves to assist your main {such as "/assist MASTERNAME" or "/assist focus"}. Put that on a bar and set a hotkey for it. I use [.
  • Now, whenever you go to a questgiver{lootable mob}, you target it with your main, tell your slaves to assist, and then hit your interact button. Everyone should open the quest window {attempt to loot/skin/herb/mine} at the same time.