In https://pokemondb.net/etymology
Sableye is said to have "sable" because of the mammal, but it's more likely from sable being an adjective meaning "black" or "dark and gloomy"
Mence in Salamence is said to come from "menace", but I think it's much more likely that the mence comes from "vehemence", meaning intense feeling or expression, a reference to how Shelgon wanted to fly so badly its DNA altered just to grow wings
Crustle is said to come from "castle" but i think its more likely a mix of "crustacean"/"crust" and "mantle" (the inside of the earth), since i don't really see what it has to do with castles apart being made of stone
i'll come back if i find more pokemon with better explanations than what's written