That tank sounded like a brick.
Rule of the thumb, just hex/sheep something. If the tank breaks it, it's not your fault.
There are a few Basic symbols to follow,
Moon = Sheep (this should be obvious, it's been said so many times.)
Diamond = Banish/Fear
Triangle = Sap/Hex/Trap
Only real constant is Sheep, rest can vary. A tank or who ever marks in the group should first and foremost inform what he wants done to the targets he marks.