I think you're trying to do too much in too little time with too few resources.
First off, let me ask you this - do you really need stormtroopers AND Pgrens AND an Ostheer sniper? That's a lot of manpower on very few squads - squads that you will always want in combat, not around the map capping. Sure you could add some Pios to the mix to cap, but now you're going to be fighting exclusively with expensive units - thus you'll be lacking any kind of true infantry based backbone, as well as reasonable access to fausts. For starters I think you cut the sniper, cut the Pgrens and just use a couple of gren squads.
Maybe something like 3x Gren, 1 MG 42, tech T2. From there you could tide yourself over with either a 251 HT or a 222 (depending on how good your vehicle micro is). By this point you should be close, if not already to Stormtroopers. Just make sure you add at least 1 PaK 40 whenever enemy vehicles would hit the field - it'll have to be quite early against USF if they went LT tech. Against Soviet you can always abuse looking into the fog for tech structures.
In order to get a Panther in any reasonable amount of time in a 1v1 you're going to be investing a lot of MP into teching, so you'll probably want to camp your side of the map more than going on the offensive so that you can bleed as little as possible. I wouldn't necessarily recommend going straight to a Panther in a 1v1, but if you do get there you should be in a really good spot. Make sure you don't hit any mines and then you can go on the offensive.
While I agree 100% with the first part of your statement...(choice of units beeing waaaayy too expensive for it to be viable) , I dont think the 3x gren 1x MG tech is solid enough vs USF at the moment (anything goes vs Soviets so feel free). Even the 222 will get wrecked by a good US player. You just cant skip Grens vs US (vs Soviets also IMO), there is no way, and 4 Grens is a minimum or you will have a very bad day. MG42 is useless right now and using it early will result in a serious lack of map control, making it so youll never get to Panthers fast enough.
LMG Grenadiers are Gold in the current Meta. Grens + PAKS (I always go for 2) can take on anything US. And then I just dont see why you would want to spend manpower AND precious munis on Stormtroopers. Pgrens do just fine...late game with Shrecks are a great counter vs any US Tank.
Finally...Panthers vs Tiger? ...Doing things for the sake of beeing different is great, but your gonna give yourself a headache. They both cost about the same (Tech cost included) and come out at the same time. But Tiger will shred EVRYTHING, while panthers cant do anything vs Infantry (which to me is the dumbest thing!!).
Storms/Panthers in a 2v2 maybe....in a 1v1 not rly.