I am not going to make an entire concept, but only make some ideas for others to use in their concepts. Some units and stuff here might also not work together, even though my first three points kinda fits into each other. well, let's go! 1: Base structuresMaybe the ostheer could be a team without basebuilding or engineers. You just start out with your main base structure like anyone, and from there you can call in commonwealth-like trucks that can only deploy once, inside your base area. this nullifies the need of engineers to build bases.
2: Defensive structuresWithout engineers, the defensive structures could be deployable. Like a MG-team that deploys into a MG-nest. You construct these units in a special defensive truck/building. Other of these units are mortar nest teams or mobile flak 88s. All these units can be deployed only once, and then work like any defensive structure.
3: RepairsSince there are no engineers, you must construct a special "repair-unit". The unit could be a vehicle that you can command over to repair something. It drives there and two mechanics comes out and repairs the building or vehicle, when they are finished the mechanics gets back into the vehicle.
Here are some units that Ostheer could use. I like the veteran system where you can upgrade your squads when they gain veterancy. It is not my idea and i can't remember who thought of it, but all credits to you. And I will only name some of these upgrades I think would fit in. And also I think Ostheer should get some kind of zeal like PE so the man next to someone who kills an enemy also gets xp. This way unarmed units can gain vet TrucksBoth Wher and PE use halftracks, so maybe Ostheer could use trucks. It is cheap and fast, but cannot attack and gets destroyed easily. But when it gets destroyed almost everyone inside survives, unlike the few that survives in a halftrack. This is because it is so easy to get out. But the units that's inside the truck can be killed by handguns or a t90. Can get armor against handguns through vet.
LMG-squadOstheer could use LMG-squads instead of HMGs. The LMG-squad is a little like wher grenadiers with MG42, but are a little more like a HMG-squad. They start out with only one MG42, but can get another one through vet. The pros and cons of this is that they have higher mobility and can retreat faster, but they can also be pinned.
Urban Combat teamA four man squad with MP40. Is very though and die slowly. Can get, through vet, the choice between MP44s or a flamethrower.
Basic infantryFive man squad squad armed with Kar98. Not very well-trained soldiers. Are mostly for conscript-killing in the start, but vets quickly, and can with full vet fight against guards. Can through vet get a sixth man, a sergeant or officer (call it whatever you like) whit an MP40 and the entire squad can get G43 (different upgrades).
So this is my suggestions, hope you like them. Feel free to use them in your concepts, and try to give some credit for them (even though I don't really expect it from you )EDITHere is three suggestions for an ontheer officer. Which one you get might be determined by Company Commander choice, or you can have one of each. OfficerAn upgrade to any unit. Adds an officer to the squad that gives suppression bonuses, faster vet and other fitting abilities. Only one unit may have officer at a time.
Tank commanderWorks like Officer, but you can't have a MG on top at the same time. Gives pretty much the same bonuses as a British command tank, but also bonuses to the tank it is in.
Artillery Commander A commander that can be put on for example a flak 88 or a German howitzer. He can spot with binoculars an he increases range and accuracy for the artillery or flak he is in.
EDIT 2Some suggestions for veterancy upgrades, units will still get fighting bonus too.Basic infantryVet 1 - Panzerfaust or grenade throw
Vet 2 - Veteran sergeant or field medic
Vet 3 - Entire squad gets G43 rifles (excellent mid- to long range combat.) or a scoped kar98 and excellent long range accuracy.
Urban assault teamVet 1 - Incendiary grenades or build mines
Vet 2 - Veteran sergeant or medic (again, maybe?)
Vet 3 - Flamethrower or stg44 assault rifles.
I personally think that Vet 1 should give an ability, Vet 2 should give a new or replace a member of the squad and Vet 3 should give new weapons. Do you have any ideas?EDIT 3Some doctrine abilitiesMesserschmitt Bf 109 (I think) - Late game abilityIs the IL-2s pissing you off? Call for air support. The Bf 109 is an ability to destroy enemy P47s, IL-2s and gliders. Just to not making IL-2 or any kind of aircraft entirely useless, it might have to wait a couple of seconds before the planes come in. Or maybe you have to lock it to a territory?
Blitzkreig - Early game abilityAll vehicles and infantry moves faster and caps faster for a short/medium duration of time. This might help against Soviets capturing the entire map.