Looks quite good. I would consider replacing the Officer squad with a late game AT strafe ability though (rocket strafe or simply Stuka CAS), as the commander lacks late game power.
I'd avoid Stuka loiter, it's already used in so many doctrines. Also feel it would be better to keep all the actual fire support in (reworked) CAS, to make that doctrine feel more unique, while this doctrine sets the focus on supplies.
How about this:
- Replace vet 1 smoke barrage on Luftwaffe Officer with vet 1 Recon Overflight (maybe Recon Pass?).
- Replace Recon Overflight with "For The Fatherland" from Overwatch (infantry have decreased received accuracy in friendly territory for duration of the ability).
Incendiary Run and For The Fatherland will always have some use, even in the late game. If FTFL is too strong, Tactical Movement could also be an option.
Early and mid game would be quite powerful with AT rifles and sandbags for Grens, as well as the weapon drop to skip T2, so I don't think the commander needs an AI squad call-in.
You're right that the early momentum might be a bit too high, I don't want to remove the officer however. The doctrine would lose most of its (potential) uniqueness. You'd no longer see med crates or incendiary run for example.
Perhaps it's better to keep FG42's behind T3 as an upgrade. That way the officer would just be a Gren squad with extra man, but be able to provide med crates to heal and buff infantry, with another supportive ability at vet 1.
It'd probably also be a bit confusing with the Artillery Officer since they'd have to use the same model.
Don't think this is a problem, only the officer model itself would be the same. The squad would have different weapons, a different retinue (Grens or Falls) and an adjusted icon to make it distinct.