So it's pretty much a sure thing that Lillie is going to win the Alola League, right?

Ash can't win because he's Ash. Lana, Sophocles, and Mallow are comic relief. Kiawe will be a "serious" contender but is ultimately comic relief as well. So who could really win? If it's between Hau, Gladion, and Lillie, I think everyone's darling has it in the bag.