Since I couldn't find an answer to this and I think I finally figured it out, I thought I might post it here in case anybody else was looking. It looks to me like the three major Japanese Frequency Dictionaries that can be added to Yomitan have a lower number for the more frequent the word, and a higher number for the less it's used. For example の has a frequency of 1, whereas 荷台 numbers are all more than 10K in the Anime & J-drama , JPDB and 国語辞典 dictionaries. Hopefully this helps somebody!
by luckycharmsbox