Yes, but why only OKW has exciting units? Flak truck, Stuka zu fuss, Luchs, Sturmtiger, Jadgtiger, King Tiger... All of these are amazing units, very rare, very powerful and they give you a lot of fun when using them. They are different, highly specialized, sometimes OP as garden but the joy is unmeasurable.
On the other hand US Forces have boring Sherman, boring Scott, boring Stuart... Shermans, Shermans all day long.
Where is Pershing? Super Pershing(), Hellcat, Calliope?
Funny fact: Only 12 game verions of flak truck were made, 18 Sturmtiger, 137 Luchs, wonder about stuka zu fuss.. Can't find... 79 Jadgtiger, 44 Ostwinds. Only one of them is doctrinal (Ostwind is non doc for Ost).
On the other hand we have over 2000 Pershings, 25 Super Pershings and 27 M26E5 Pershing with 102-279mm armor. I guess Calliope and Pershing would provide a lot of fun like OKW units.
320HP. AA truck, T70 and Stuart also have 320 but hey! They don't have smoke.
Well I can understand the allure of big tanks, but Flak truck, Stuka, Luchs etc, exciting units?
Well, different strokes for different folks I guess. I would not mind a Pershing per se, but I dont see how it would not break the already hopeless USF vs OH dynamic... hopeless as in hopeless for OH, that is. A call-in that would enable USF to out-Tiger the Tiger, what could possibly go wrong, not to mention the Pershing saw use in all of 2(?) engagements in the ETO which would not sit too well with your own criteria. Calliope, why not, Hellcat, would be pretty redundant with Wolverine, but why not, still, all of this would be just added flavour and not remedy anything of what is wrong about this game atm.
Edit: Apparently, the Pershing participated in about half a dozen engagements.