So the main things I see missing from SMB's team are important resists in Fire and Water, with zero resists currently in each case. Looking at opposing Water-types, Tapu Fini is somewhat manageable, but the team could definitely do with more to help deal with it; while on the other hand Volcanion is more easily dealt with, due to Landorus-T being able to hit it and Porygon2 being able to Toxic it more reliably. Also the rain matchup could be improved, as right now only Porygon2 can take an attack under rain without screaming to run to the nearest Pokemon Center. On the Fire-type side of things, a well played Mega Charizard-Y team (
such as Ezrael's team) can also pose some issues I feel, as unless Manectric is out or Trick Room is up, Charizard + Kyurem-B / Kartana can deal real damage to the team. Also, Incineroar can be quite annoying, by Flare Blitzing Celesteela, removing Porygon2's Eviolite, and pivoting as it pleases; as even with double Intimidate to weaken it, Landorus-T is the only present team member which really threatens it.