ok? And? Look I've been playing since Gen 1. I know how to raise my team. In Game doesn't have that lethal of an AI that you can go through it with one specific type and have little trouble. The team in my signature is an In game team. Its not meant to be perfect. It got me through to the end which was its purpose.
There are also competitive teams that use more than one of similar types that share the same weakness. I'm not the first to use more than one Pokemon that share at least one weakness. I won't be the last either.
Well it's important that teams can't repeat the same type with two diferent Pokemon unless they have different weaknesses (Ex: using Empoleon and Scizor), because your team will be at a huge disadvantage against a certain type on both in-game and competitively.