Thalnazpic christendom (Universal in Etruscan) is this thalnazpic's catholic faith. It is a remnant of the Etruscan Empire of the classical age. The Aranthurian faith is somewhat politically similar to the protestant faith, although differ wildly in theology - and has existed far longer. Etruscan religion is obviously not super well known but given the potential time frames your thinking it could work and it can just creative licensing on that. Etruscans which for whatever reason have been placed on the most Earth-like planet in the system along with fauna and flora around 2000 years ago.