German Jews not only fought for the British because of their persecution back in Germany but also because the British held the Mandate over Palestine which could be negotiated as the future Israel (which it ultimately was). Many Jews from all over Europe fought for the British whilst the Arabs sided with the Axis powers as victory for them would give the most chance for Palestinian independence from the British.
Those were true Germans trying to remove Hitler as head of state so they could bring some sanity back to their nation before it was too late. Not really the same as Germans fighting their own nation, most German soldiers were proud to fight for their country and didn't share the Nazi ideology that corrupted their government.