I have family on all three sides of this... German, Polish/Ukrainian and Ashkenazi...and let me state, the Slavs were the most anti-Semitic post World War II of any ethnic group I’ve come across. That Poles actively cooperated and compensated over and above with Nazi edicts, no surprise.
Are there stereotypes, sure. But stereotypes always have some truth at their base.
Prove that this was done on a mass scale, any more than a few individuals. All the documents that I have seen including by Jan T Gross, talk of, in terms of facts, isolated incidents.