This book's purpose is to prove the thesis that the Barbarians were not given 1/3 the land of the Roman provinces they initially took over, but got the 1/3rd in Tax Money instead. It's slow going and a little dull. The English translation from German sounds a little turgid, but I don't know German. If you have to read it; read it. If not you may wish to look at Peter Heather's The Fall of The Roman Empire.