That depends
For example, when making the fortresses into my OOB pack, I've included them in too much details I'd say because it was fun
Of course included parts that never made it to field service - like 10cm model 1938 howitzers or rotating turret for them etc...
Depends completely on what you do think is approppriate. Is it good to have the Super Pershing in OOB or not? Is it good to add M6 heavy tank as a what if? Or Sherman with 90mm Pershing-like turret? etc. etc.