Poetic Justice!!!

Look they are much too powerful to start with and most nobles killed were tried by the King and not the Church. Obviously a priest or friar might just disappear or accidentally fall from the battlements, with a hearty cheer from those fellows joined in to watch.

I did a good job of them with assassins until one was caught and I was excommunicated for the trouble.

A royal military option seems more than plausible and should not be changed