0) Do bunch up early. Like not blob, but keep troops close to each other
OKW is the faction benefiting most from having all units in one place, you will try to concentrate your forces in one place and fight head on, you will lose to okw.
1)Identify his teching
You can safely bet he will go mechanized and if its needed, backteching to med truck is cheap af
2) Medical HQ means lack of hard-counters to support weapons and indirect fire, so make a hell-load of those, but of course keep infantry nearby
You go team weapons heavy vs mechanized? Here go stuka with luchs and puma into command panther.
3) Repairs HQ means a possible stuka and also LVs, but lack of healing. Focus on ammo points rather than fuel, get weapon unlocks, do lots of baiting for flame nades, an AT gun and (situationaly) try to avoid gettin LVs yourself. Support weapons are still a good call, but not many of them
"Lack of healing"? You know sturms can drop med crates? And please dont act like okw is struggling with munitions, if not flame nades, you will get hit with 15 muni infiltration nades. Also good luck surviving as any allied faction against mechanized heavy build without light vehicle yourself.