Its hard to suggest something without knowing which german division.
But, theres a fair few things, air attack is the main thing that bugs me as a 15th inf player(if the brit brings planes, just bait him into your AA and then send your own fighter to kill them, then bomb away), that and panthers using their range advantage with recon to push me back when I show myself. AVRE is tough, but if you manage to panic mode it, not that bad anymore.
Luftbros have a hard time of it if they lose in phase A against them though I have yet to see a luftbro spawn a single damn tank against me (including stug here i know not a tank) so i mean, yeah, you wont get far without armour, but really its hard to judge "op vs not op" with only 4 divisions, afterall, it might not be that 1 division here is OP but that others are weak in comparason with the other 14 divisions not yet in the field.
Finally, the 15th dont get all that many apcs, they only come with recon, command and iirc a couple in the anti tank section, much like others IIRC.