Sherpa is commonly misused to mean "expert", in particular in marketing. Sherpa is an ethnic group and using it to mean these synonyms is appropriative.

Alternatives (n.):

• aficionado
• consultant
• connoisseur
• expert
• professional
• specialist

Source:
https://qz.com/128842/the-problem-with-calling-your-career-coach-a-sherpa/

You should order masks by efficiency (occurrences/key_space) because this will lead to the less guesses to crack passwords.

Looking at the top 5:
https://github.com/kaonashi-passwords/Kaonashi/blob/5239bd333ed34993b43126a4499606ba70086034/masks/kaonashi_masks_numbered.txt#L1-L5

And ordering just the 1000 in kaonashi_masks_numbered.txt by efficiency the top 5 are now:

673407:?u?u?u?u