I'm not sure how to feel about this episode. It was nice to see the boys working together again, but at the same time, I wish the girls hadn't been shoved aside. Would it have been so hard to have all six students working together, or at least show a few more minutes of what the girls were doing
besides running into Hikers?
I'm not sure why the Ultra Guardians were needed for this mission. Aside from the magnetic field interfering with the Ultra Aura sensors, this really had nothing to do with the Ultra Guardians or the Aether Foundation. Lusamine, Professor Burnet, or Wicke could have easily investigated this matter themselves, without getting the Ultra Guardians involved. Ash and his friends could have been visiting Wela Volcano for another reason, and Kiawe could have noticed the Alolan Geodude and Graveler being above ground as an unusual sight simply because he is familiar with Wela Volcano. The only difference would be that Metagross wouldn't have been involved, and we wouldn't have had that "battle" between it and Alolan Golem.
Speaking of which... After all that, I thought Alolan Golem would decide to join Sophocles (who, as far as it knew, was Metagross's Trainer; it has no way of knowing Metagross is just Sophocles's Ride Pokémon), but instead, it decided to join the Hikers for...no apparent reason I could think of, other than perhaps liking their spirit.
WTF was going on with Metang apparently 'attracting' and attaching the magnetic body parts of Alolan Golem to itself??? Doesn't really make any sense via Pokelogic.
As Rotom explained, Alolan Golem's "eyebrows" are made of iron sand. The only explanation I can think of is that since Metagross's body is made of metal, it attracted the iron sand to it because it's magnetic. It actually made sense to me.