“Is Waincraft a type of religion based around historic and/or archaeological research into the parent group of the Indo-European Language? Or is it more about synchronizing commonalities in the descendants of that parent group?
A little of column A, a little of column B. However, Waincraft is less focused on language/linguistic groups and more on the essence of how spirits have manifested in particular landscapes.
But defining that essence required pretty equal amounts of intense research into varying European and neighboring Eurasian cultures and their extant mythologies, and cross cultural comparison to find commonalities that might speak to the “god behind the gods” sort of concept. The goal was to figure out what sorts of spirits are truly and uniquely tied to a particular place, and what sorts are more universal, and which qualities define those more universal spirits across all their manifestations, and which are due to localization.
Also, Waincraft is not a theistic-centric religion, but closer to traditional animism. It recognizes and honors several different types of other-than-human beings and its practitioners are not required to work with all of those types equally. Some may just want to work with the Tribes, or with the dead, or the gods, or one spirit in particular. The only thing that is required to consider oneself a follower of Waincraft is a dedication to the ideal of orthopsychy and a sincere desire with appropriate actions to reconnect with the world around one, all the rest is window dressing (the cosmology and theology are designed to help with these core bits, but are not necessarily compulsory if they don’t speak to a particular person).