The model certainly has some obvious flaws like you noticed with Dynamo and Powerstone. I don't think it "counts" words or symbols on cards and it definitely doesn't have a notion of the "role" a card might play in a deck other than its key words.

I like using it when I have a card that has a niche intersection of mechanics/words and I want to find all the cards that are as similar as possible without manually searching every possible subset of those mechanics or words.