It looks like it selects the default archive manager (or asks) if there are multiple available ones in the /usr/lib/xfce4/thunar-archive-plugin folder. So no need to rename the other files, just make p7zip your default archiver.
It looks like it selects the default archive manager (or asks) if there are multiple available ones in the /usr/lib/xfce4/thunar-archive-plugin folder. So no need to rename the other files, just make p7zip your default archiver.