The hetzer is actually really really good, but it's stuck in a lame doctrine.
I personally don't use any of the abilities other than Stuka and Flame Hetzer.
We could easily turn the Opel Blitz into a mobile cache like the Ostheer variant. That would assist in a Hetzer rush strategy and have some synergy. Not sure why the balance team decided to give OKW a blob support unit instead. There are people out there that insist on playing it the most obnoxious way possible just rushing your cut off with 4 Volks + Opel and then having infinite reinforcement there. There was a reason why Relic didn't give OKW a mobile reinforcement vehicle. If they want to keep it as it is they should just reduce the price and make it a OKW ambulance with same stats as the USF one.
Then rework MP40 Volk package and Sturmpioneer flamer upgrade into something that isn't as awkward and has synergy.
You get Flamer on Sturmpioneers to clear out a garrison but regular Volks already have the flame grenade so there isn't much point in it. Then you can't get a sweeper unless you get another Sturmpioneer which is super expensive and generally something you want to avoid at all costs. The MP40 Volks are pretty strong but worse than STG Volks for late game because they require a ton more micro which you would rather spend on vehicles, rocket artillery etc.