If the two years of this game indicates anything, it's that this is supposed to be how the game works.
So another upgrade after you go all three officers just to unlock another three units? Wouldn't this do the exact opposite of what you want, Jackson comes even later? Jumbo's not going to happen, especially as non-doc, it would just replace regular M4. If there's a durability issue then M4 should just get armour buff via veterancy or munitions upgrade, not a discrete unit that makes other units redundant.
Priest on top of M8 HMC, pack howitzer, major airstrike and doctrinal abilities? What is this, Total War?
Jackson come later is exactly what I want. I'm not here to buff allied.
Jumbo is just a suggestion. Its cost in comparison will give player second thought about their choice. Just like Panther or Panzer IV.
This is topic about late stock, so leave commander out of argument. Pack is just nothing but a regular mortar now and M8 HMC work only at short range.
The helpless feeling when late game hits USF and Sov, as you choose weak commander (Mechanized, Recon, or NKVD Rifle, Urban...) should be problem to be solved.
And by the way, the T34 spamming is just an example. I have seen ostheer with panther spam and still make a great success, while T34 spam can only work if you have already been winning.