You are also not including timing and the later teching stages (to be fair, the latter one wasn't what you were talking about). Sure, the match-up is kind of fair, even though Ostheer pays more manpower and ammo for the same service. But when you start to include that Ostheer has a longer research AND has to pull back a scouting/flanking unit from the front to then start building that stupid building, you suddenly lag even further behind.
On top of that come the American officers. With every tech, you get a free unit. A unit that in most cases can more than just go toe to toe with Ostheer infantry. And those free units come with more than just combat capability. Every good player will use their Captain to pump out a Stuart even faster. Or just take a look at the Major's forward retreat, something that Ostheer doesn't have at all and something that OKW has to pay dearly to get.
These things are simply not well-thought out. Sure, they make for a cool faction, but not for a balanced game. The community was happy when the OKW free teching benefits were gone, and rightly so. Now we need the same thing to happen to USF.
USF = free lt/cpt/major
Ostheer = free pfaust/grenade/lmg unlock. We can also argue that shrecks are freely unlocked for pzgren.
I also let you check lt building time compared to Ostheer T2. BP1 is something you need to unlock asap when you reach the fuel requirement, that's why it only cost 100mp. Once unlock you should have or almost have the resource to build T2 which takes much less time than building lt/cpt.
I agree on the fact ostheer/sov need engies to build up their tiers building and this could be something changed in order to balance the game.
And it doesn't change my conclusion, yes Oshteer is underwhelming vs USF, but it wasn't the case before the introduction of the mortar.