Sorry, but Spaetzle is not served with Wienerschitzel (Vienna schnitzel) which btw is made from Veal. Schnitzel is served either with German Potato salad, french fries or home fries
Spaetzle on the other hand are served with pork or beef roast
When I was stationed in Germany many, MANY years ago, it seemed every
gasthaus I frequented had spaetzele as a side with the schnitzel. Of course, it could have been a regional thing.
I was never offered German potato salad.