A Soviet commander that gets bunkers would certainly be very unique and fun. Maybe merge the mines & traps together and include bunkers, as an engineer defense package.
Then add an ISU-152 in the last slot.
I think this is rather ridiculous, I believe that each faction should be able to build defensive structures without doctrine (only the Soviets can't, OKW can build 37-mm HQ + 20 AA and a machine gun bunker with doctrines) and anti-tank traps without doctrine.