I know both Classical Chinese and Sanskrit and have no idea what you are talking about.

"It's rare in both languages to stumble across a word that is just a black box, whose etymology you can't pull apart so as to guess what it means."

Err, yeah I guess you can guess from the morpheme of a Chinese character that a particular character is a type of tree or has something to do with trees, but that's about it. Similarly with Sanskrit, because of sandhi rules often times you can't even figure out what the word is in advance, and I'm not sure how you are suppose to "guess" the meaning absent looking it up in Monier Williams (unless you are guessing backwards from other Indo-European languages, in which case your potential guessable vocabulary will be quite small).