Hi, not sure re Germany but, if it helps, the latest estimate by academics is that circa 50% of the population in England (note not Wales or Scotland) was literate by the 1630’s (thus explaining the huge political influence of the political pamphlets - mid C17th “fake news” - in the build up to the ECW). My understanding is that parts of HRE were at least as literate as England, if not more so (although my TYW knowledge is still, sadly, too limited to be useful in this regard).
As the TYW progressed the religious make up of the armies becomes, at best, “confused” and one would have found many Lutherans fighting for the Emperor or the League and Catholics in Protestant Armies (eg the Parliamentarian General Sydnam Poyntz fought in both the armies of Saxony and Wallenstein, and the Protestant General Ernst Von Mansfeld was a Catholic so all things are possible!).
In short, as I see it, you are at liberty to do as you want with your amazing figures....... in my opinion.
I am loving following your project! Thank you, so much, for sharing!