Most of your poke are correct, except Flaafy, I recommend changing it for another poke mentioned below.
Flying Pokemon against Marshal & Alder's Volcarona, like Archeops or Gliscor. Serious, Marshal's team is mostly a single fight typing.
Ice/Dragon Pokemon against Iris & Cynthia, like Weavile or Haxorus. Although some of your Pokemon can learn Dragon moves, like Arcanine's Outrage, maybe.
Just keep in mind Fire Pokemon like White Kyurem & Chandelure are going to be a threat.