CaptainObvious:

There are no useless units in the game. I've been impressed with each of them at one point or another.

Wolverines with dual launchers are a pretty fierce unit. Try a bunch of them against a hog rush sometime and see what happens.

I must disagree.  The one and only unit I find useless are the Grunts.  I don't see any point in making them at all. 

They are good against air but why buy them when you can get Vamps?  The one and only time I would ever buy a grunt squad would be an early air rush when I don't have a summit for vamps.

As far as Wolverines go, they are a great compliment to any army you can muster.  I recommend them 100%