It’s not necessarily either/or. It could be a mixed situation. With nominal Catholics who were not Christian (or at best were confused) participating in the massacre.
You are correct in that there were some nominal Catholics who aided the Nazis as well as the Communists. The problem is both the Nazis and the Communists used that participation to impugn all Poles as well as the Catholic Church at large as willing participants in the Holocaust. For the Nazis, it gave them the images which used to portray themselves as if they had an approved moral cause. For the Communists, it gave them the cover to label all Polish enemies of the Soviets as Nazi collaborators after the war....Which is the message which is still repeated in popular media with regard to Poland today.
This wouldn't be the first time in European History that Jewish communities were slaughtered by their Christian neighbors. In the past, religion had little to do with Christian's motive for perpetrating these crimes; they simply used religion as an excuse to murder Jews and take their property.
If you can determine what happened to Jewish property after they were murdered, you will probably come a little closer to truth. More than likely, this wasn't a case of religious fervor; it was simply greed at its ugliest.
As always, "Follow the Money" and you'll usually discover the motive and then the perpetrator.
I lived in a small town near Ramstein for almost 20 years. In this small village....I came to note one day that there were two Jewish cemeteries in the local area. Both had gravestones that kinda ended around 1940.
It’s safe to say that there were a number of Jews in this little farming community in the 1930s....between my village and the next one over. I can only guess that roughly thirty farms were operated by them. Then one day...they were picked up.
It’s a curious thing that the village doesn’t talk on. I came to realize that around 1940...my village and the next one over....combined into one community. This unification lasted until 1947, and they divided. The farm property belonging to the Jews? Likely disappeared into the paperwork of the unification and the breakup of the two towns.
Some German families got the property and no one said much. It’s not a Catholic community, but there are two heavily favored protestant churches in the local area. One of the churches was barely 500 feet from the Jewish farming section.
My humble guess is that a lot of religious behavior got out into the Nazi business....and lots of people did their brand of pay-back.