I kind of enjoy the shrek-track. Eats T-70s - nice having a hard counter. Like, it could probably have the mp cost cut a little for what it is.
That's 560mp, 120mu, and 55fu for a "hard counter" to a 160mp, 55fu unit that probably won't be able to do anything else later in the game (considering there won't be any Su-85's or Katyushas to flank if they went T3). Not the most efficient use of resources, don't you think?
I mean, just compare the cost of it to the T70. It costs 40 more manpower than that infantry killing beast and has no weapons by itself whatsoever. I'm not saying it's completely useless but it's pretty hard to find a place for it in the vast majority of situations.
This call-in and the Stug-E have too high of an opportunity cost (delayed T3 -> Ostwinds/Panzer IVs) versus the minimal utility they bring to the table (do not really fill any major gaps in the German arsenal). Compare these call-ins to the Mortar Halftrack and you'll see what I mean.
Frankly, this is actually a related issue to the M3 being a bit underpowered because both have a very limited window of usefulness before they are completely outclassed by tank spam or rendered a liability due to other AT.