It was explained in the LL that eventually an Arcanist will have to choose which they prefer - SCH or SMN.

Quote Originally Posted by Reinheart LL translation
y; up till lv50 the gear goes for both jobs so scholar is MND and sumoner is INT
y; once post 50 we want players to decide which to go with
from Reinheart's translation/googledoc https://docs.google.com/document/d/1...pli=1&sle=true

So for instance for me I would probably re-do all my ACN stats to MND once I am 50 because I would focus on SCH only. I may change my mind but for now that's what I personally think I will do.