It sounds like there will be several levels to creatures.
Roled Creatures (Skirmisher, Brute, etc)
Elite Creatures
and then Minion creatures.
Minion creatures will most likely be easy to kill and not be much of a combat threat, such as low HP, little chance to hit and not able to crit. They will be the creatures that PCs can just wade through.
That is the impression I have been getting from everything.