And Osts Achilles heel is lack of indirect fire and vulnerability to protracted MP bleed.
I getcha on the last part, not so much the first. Germans feel the MP bleed more than the soviets mostly due in part to needing to field high MP late game tanks. Soviets don't have late game tanks that don't also take 240+ fuel so they're a bit free to not have to float up to 600-700 manpower.
Also when adding up the cost of tier buildings and tech, it's probably worth taking into account what units and upgrades each faction might need or want before the first tank hits the field.
Soviets have the choice to spend fuel on m3 scout cars, AT nades, and molotovs. The latter two of which are almost necessities to conscript competency and utility. Scout cars are an expensive unit fuel-wise in the early game (20) and are essentially hard countered by the German's base unit's first ability: panzerfaust.
Germans have the choice to spend fuel before t3 to field Scout Cars and Halftracks. Scout cars are very effective units for the early game, but they can be ignored. Halftracks are kind of the flagship early game unit for the Germans, especially with the flame upgrade.
With this in mind, Soviet players are generally assumed to have invested 50 fuel into equipping their conscripts to handle German t1 and t2. German players have a choice to spend fuel to field units that are effective counters to soviet t0 and t1. (and two of the three units from their t2.) It's actually rather balanced, with the initiative of course being in the favor of germans due to them having access to a complete army.
But essentially the point is: those resources spent on upgrading conscripts are more expensive than a scout car or halftrack, and the conscripts themselves remain just as flimsy, and only providing the soviet player with the option for spending munitions to soft counter. Where soviets have to invest to counter, germans can invest in two mobile units, one that reinforces squads and can be upgraded to effectively force soviets into getting ATnades or some kind of ATG, and another that can be upgraded to hard counter m3 scoutcars and soviet infantry without AT (penals, shocks, conscripts where the player hasn't spent fuel on AT nades).
If the soviet player skips t1 or t2, but still gets molotovs and AT nades (soviets are often kind of forced to) and manages to maintain the same resource income/map control as a german opponent rushing t3, a t34 will hit the field a bit later than a p4: 20-30 fuel later.
Which is why no soviet player that gets ATnades and molotovs in their right mind goes t1 and t2, because being 80 fuel behind for the ostwind or p4 is pretty devastating.