I disagree, the Ju-87G would be in about the same class as the Hurri-2D and the Il-2.
Contrary to popular belief, (or maybe not contrary, I dunno), the .50 and Hispano COULD (repeat, COULD) penetrate the armor on the Panzer IV. It could get through the roof at a range of 300ish yards. Add in the speed of the plane and those rounds would be able to penetrate the armor at slightly longer ranges.
So.. what sets the Hurri-2D and IL-2 apart? Well, a Hurri-2C or Spitfire can knock out a Panzer IV's turret and engine easily enough (the .50 planes have a slightly tougher time, as does the Typhoon, mostly because if you get inside of 300 yards with one of those at the angle you need to get through the armor, you'll have a helluva time pulling out), but they can't do a thing against the Tiger.
A Hurri-2D can knock out the Tigers turret with the same kind of attack you use to knock out a Panzer IV's turret. And IL-2 can do the same thing.
A G model stucka, if we got one, would be in the same class as those. It would be actually kind of like a German Hurri-2D, except not as manueverable in A2A combat.
I'd kill to see one.
By the way, the 110 and 190F8 make reasonable tankbusters now, they can knock out the engine and turrets on a Panzer IV with the MG-151 now, as of 1 or 2 patches ago.