Also bear in mind that Germany as a nation was formed in 1871 after successful European wars wars by one of the states, Prussia and before that Germany had been divided into dozens of small states.
This was the old Holy Roman Empire of the German nation, which had existed for 900 years when it finally collapsed under Napoleonic pressure. It was known, between 1815 & 1871 as the German confederation
https://en.wikipedia.org/wiki/German_ConfederationWhen looking for 'German' armies prior to 1871 it is *probably/possibly* best to look for armies etc of the states making up the confederation.
ETA*