I don't mean have one team through the whole game, but really most people's teams I've seen have been the exact same......
They all have an Ice, Dragon, Rock, and Ghost type. Then the majority of people I've seen all picked Torchic, Charmander, or Greninja as their starters.
So everyone is using the same powerhouse team, it's just you have to know what team that is going in or you get screwed like I am at Ciel where I can't do anything but I'm not wasting time grinding up a certain mon 30 levels for this one fight