Three things to ease Prussian set up:
1. All Prussians that begin on the map begin on either the South or Central maps. So when setting up, don't bother looking at the North map.
2. All starting positions are associated with towns or villages, and those towns or villages are labeled in red print. If nothing starts near a town or village, it is labeled in black print. So ignore black printed villages; etc.
3. Unlike the usual practice of reading the set-up position in the rulebook and then searching the map for that place, instead, locate a red place (see #2) on the map and then look at the rulebook set-up and see what starts there. If nothing is actually listed as starting there, then that place belongs to another scenario's set-up.
Another thing is that commands are somewhat grouped. So, though Prince Louis begins with most of his corps near Rudolstadt, the rest of it begins in villages located in that general corner of the map stretching down to Saalfeld. There are still some places tucked away, however. Neustadt and Auma, for instance, always throw me for a loop. Both are on the South map: Neustadt is practically where the South map meets the Center map, but towards the middle; Auma is ten hexes south-east of Neustadt.