1) Model the Ostheer after the Wehrmacht faction (the same core units and structures). The Ostheer were simply the Wehrmacht in the east.
Than play as wehrmacht.
2) The Ostheer should either use "Doctrines" (see suggestion number 1) or "Groups" - Army Group North, Army Group Center, Army Group South. Each "Group" would have specific units and abilities accurate to history.
I dont like the North, Center, South doctrine names.
A doctrine that has armored call-ins and field repairs should be called armored breakthru or engineer.
A doctrine that has entrenched positions and cheap infantry should be called infantry or propaganda.
North, Center, South dont point out what the doctrines are really about.
3) Unit: Italian Reinforcement Squad (if "Groups" are chosen, specific to Army Group South) - the German Army in Crimea and southern Russia was backed by armies of several Axis countries, one being Italy. This unit would be called in much like Partisans for the Soviets.
You know that Partisants can be called the same way as Falshimjeagers. Out of empty houses?
Anyway, every EF player wants a non german axis unit.
A whole Tier I could be Italian/Romanian/Hungarian:
http://easternfront.org/forums/index.php?topic=2876.0