>>31281410The reason they probably decided to have Kaki, Lana, and Mallow appear early on was to build them up for their future trials.
After this weeks episode I'm pretty confident in the fact that the Pokemon School is going to be a thing for the entire series. It's going to be used as a hub for all the characters to be together and get screen time, but when it comes time for a trial we'll see one of the captains go off in preparation for Ashs arrival similar to Clemont going to train before the BroBowl.
They'll do this with each of the core group so that we know a decent amount about each trial captain instead of having them be similar to Gym Leaders who only get 1-2 episodes of screen time per series.
