>>38303424USUM is better overall.
First two are basically the same but get rematches.
Araquanid has some cons, but I think it's a big improvement.
Pros: It has a 180bp bubble, leech live for recovery, and aurora beam, an egg move, to screw with the comedy relief owl or if you traded for a noibat. Masquerain is also great at lowering speed, and a wacan berry slightly helps to cover for an electric attack.
Cons: Totem wishiwashi had higher stats in schooling form. Had alomomola as an ally which is incredibly broken with healer + heal pulse. You can get flynium Z, but nothing is really strong enough to Ohko with it at this point anyways.
Marowak flat out summons the old totem and isn't one shotted by mudbray. It hits harder with the bone club, and it has some extra coverage with brick break. It can still pull off the poison venoshock wombo combo with salazzle while also using hex to add to it. Detect could also make you wiff on your z-move too I guess.
Lurantis now has two sun setters instead of just Castform. It also has low kick now, so it's walled by less. Comfey also means priority healing on top of Lurantises own synthesis. That and defense boosts via flower shield for lurantis.