The appearance of Naval Infantry dosnt make Strelky less affective.
Shreck Stormtroopers, Puma and Nebel is a great trio that can defeat most allied treats. Tech up to get Sharpshooters (becouse ST are expensive to reinforce and have only 4 men) AT guns (with infantry support) and get a SU (76 or 85) ASAP but keep it out back only in case of a puma flank - it shouldnt be exposed to Shreck sneek attack. Since Pumas will shoot at your infantry and force them to retreat get a Medic truck.
Those are only basic things but there is no easy counter to Wehrmacht. They just tarde cloaking Paks and Grens into Stroopers, Mortars and Stukas to Nebels and Ostwinds, PzIV and Panthers to Pumas, StuGs and Tigers. T1, T3 strat is still very flexible strategy, like Ive said it can defeat most allied treats.