Man am I so glad I'm in Ravenclaw.
Right now I agree with the fact the overpopulation of Sorcerer's is stunning, but it also is the same for Trooper's on the Pub side. And relatively they are all 1 button mashers.
The problem with your idea of Commandos/Mercs is this: some might spam grav/tracer but most don't and that ones that do are worthless and should be the easiest kill of all classes. What you "see" is grav/tracer spam because all but 1 other single target ability are instant casts that are buffed by using grav/tracer. You most likely see 3 or 4 grav/tracers in a 10-15 second span and what you failed to see is the High Impact Bolt that hit you along with the demo and sticky grenade (sorry i don't know the Imp names)