I would like to suggest removing trenches from osttruppen doctrine (and give them something else) and allow them to being build by pioneers and combat engineers to compensate lack of regular sandbags and other infantry defenses.
Also I suggest adding soviet DShK emplacement (like in HQ) for combat engineers that will cost in manpower and small amount of fuel.
I will be delighted to hear feedback from other users about this issue

Cheers !