The effect is translated as :
①: The following effects are applied depending on the number of "black magician" "black magician girl" in each other field · cemetery. 

This effect also is " in each other field " , so make it LOCATION_ONFIELD in case of Dark Magicians being treated as Equip Cards , same as here : https://github.com/Fluorohydride/ygopro-scripts/pull/732

A lot of old cards i think need an update , if we follow that , especialy if it says "If "[X]" exists on field" , cuz if its says , "X monster" then u know its always LOCATION_MZONE , and u wont have to mention about the SZONE

Thank You!