Yeah, powercleans are done from the floor. Starting position is same as a deadlift.
I see your point Anuj. What I'm saying is that if I'm doing 'lower rep' powercleans (somewhere around 5), in that range I can deadlift 300+ but I can only powerclean somewhere around 150lbs (on a good day

). By my logic, my abillity will be limited heavily by my shoulders (upper) and never by my deadlifting (lower).
I didn't factor in the front squat though, even with it in, I still think my shoulders would be the limiting factor. I'm classifying it based on what my 'weakest link' is.
I think both of our views are valid though imho, and it's 6 or 1/2 dozen of the other.