Evidence for 2 rules linking words in Herbal A->B

[ololololo]

The scenario I like to imagine is that the language is an invented one and that there was no formal guide or reference for it

There was a method they adhered to. But I can’t explain why they consistently followed this rule.
The weary scribe Quire 13 could simply start writing nonsense like dpqokyln. In the case of a forgery, it doesn’t matter so much what words are written. It’s enough that this text is simply written.