Building stone mansions over clay huts is fine unless you don’t kill villagers first. (!!!) At the beginning Teutonic Knights seemed like a fine priory of God, I agree, But when Lithuania got baptised, TK. influence over that part of Europe decreased. (They have been raiding Lithuania, as it wasa pagan land.) They couldn’t bear it... And they have started a war against Polish (yes, capital here) and Lithuanian forces... Now tell me, If they were really Christians, why would they start a war with other Christian country? What was a case here? Religion? Faith? Believes?... Not really. Justmoney... Finally they got their asses whooped on 15.VII.1410 and never regained strenght... Thank You God!
You can’t possibly know about their motivations, the character of the pagans or how the knights were viewed by the public in the conquered territories. Maybe they were viewed as quite OK compared to the people who reigned over this region before they came.
I doubt the people back than had the Polish national conscience the author of this book (and I suspect there are many others using this old happenings for their modern day aims) attributes to them.