This thin (80p) booklet (about A3 size) is largely a collection of commented photos.
In the very Vorwort, the author informs us that the actual book of reference for people interesteed in unit markings, is not the one you've recently bought but quite another - namely "Die Truppenkennzeichen der Verbände und Einheiten der deutschen Wehrmacht und Waffen SS under ihre Einsätze im Zweiten Weltkrieg 1939-1945", a four-volume-work by Schmitz and Thies.
I agree, anyone looking for a systematic and exhaustive description of unit markings should by those volumes instead.
Fleischers booklet offers a range of interesting photos, many seem unpublished and Fleischer's knowledgeable commentary is interesting. But that's it.