Great idea. This is why my buddy Maphead argued that it is actually better to put forces in Denmark than WG. Since you may not be able to stack both or all 3, and your heartland is only vulnerable if Denmark is lost, the fortress stack is better put in Denmark, than either Germany or West Germany.
This is especially true in G42 and G41, where the allies are all over Germany from start.
A partial remedy to some of your Germany-fleet smashing plans is that they can put 3 airbases to protect SZ 113. In most situations, bases are less flexible than carriers. But for Germany, the bases allow you to have the fighters on the ground ready to protect your stacks, while at the same time, potentially adding 9 fighters to your BB CV CA fleet, for a total of 16 brutal defenders–only 1 of which you abs had to buy. The bases are not typically used to add movement or assist an attack (going against my rule of having at least 2 situational goals in mind when placing a base), but if they save Germany and Germany kills Russia, it was worth the $100 payday.
Italy can kind of do the same thing to protect its fleet (97 can have 5 bases, 95 probably only 2), if the fighters (from either team) are available, and they can do both plans in response to the what vital areas the Allies seem ready to target.