It's beautiful, but not always accurate. For example, Silesians did not inhabit whole entirety of region known later as Silesia - easternmost parts of what would become
Upper Silesia were part of Lesser Poland (so, in tribal times inhabited by Vistulans, not by Silesians), while western part of this region were inhabited by Opolans (hence city
Opole), who were completely separate tribe not dependent on Silesian tribal leadership. While speaking of Lower Silesia, northwesternmost part of it, bordering Sorbs was held by another tribe, called
Dziadoszanie and their "capital" was in
Głogów, and the southwest was held by
Bobrzanie, who inhabited lands around river
Bóbr. Silesians only held lands around
mount Ślęża, which was a place of sun worship for local Slavs. Silesia as a region is a byproduct of Piast dukes and their administration. And Prussians did not held lands as far as Vistula -
Chełmno Land, which you marked as a part of Prussia was inhabited by
Kuyavians and other lands, which you marked as a Sudovian/Galindian were inhabited by Mazovians (not Mozavians). Also White Croatia was bullshit, Croats by the time of even POD (and these events are far removed from POD) were long gone to Balkans and so-called
Grody Czerwień