here is how websters defines stack:
stack
verb
Definition of STACK
transitive verb
1
a : to arrange in a stack : pile
b : to pile in or on <stacked the table with books> <stack the dishwasher>
so this does NOT mean to NOT STACK, stack means to stack, spread out means to not stack
when the tank says STACK ON ME SO WHEN THE 22 MOBS THAT LIKE TO CHARGE RANGED WANT TO CHARGE A RANGED, there is no ranged to charge
guess what happens then
they don't charge
so remember, stack does NOT mean to not stack, it means to stack
so stack, stupids, i want your toon within melee range of my toon, if i could cleave you, i want you to be so close that i'd cleave you
and remember, you CAN STACK BEHIND the mobs to avoid the big mean bad guy's cleave as well, that is also common sense that the stupids do not understand.