Much as I'm generally not keen on CR stuff and will never not be salty about them accidentally turning D&D firbolgs into cow folk, the name "dunamancy" is actually a bit better than that. It's just based on another meaning of the Greek word that "dyna-" comes from. This version is better translated as "potentiality" or "possibility". Aristotle used it for a bunch of stuff, so it got brought into English with that meaning as "dunamis". The -mancy bit is definitely just because fantasy stuff uses it to mean any magic though