Lower numbers are if they have type advantage and a good moveset, Higher numbers are for non type advantage Pokemon. These games can be really difficult, if possible go to the higher end of the spectrum.
Kahuna's
Hala:
Levels 12-16
Olivia:
Levels 24-28
Nanu:
Levels 35-39
Hapu:
Levels 45-49
Totem's
Gumshoos/Raticate
Levels 8-13
Araquanid/Wishiwashi
Levels 17-21
Marowak/Salazzle
Levels 22-26
Lurantis
Levels 22-26
Togedamaru/Vikavolt
Levels 31-35
Mimikyu
Levels 31-35
Kommo-o
Levels 43-47
Ribombee
Levels 53-57
Hope I helped!