I find your team to be fairly, obvious . . .
Let me explain . . .
Dragonite is a OU pokemon (I will assume that you know all about teirs) with a 4x weakness to ice. Several other OU pokemon share that same weakness (Salamance, Flygon, etc.) so most people have someone with a HP ice attack on their team. You could very easily be less predictable or more creative with this.
The Blissy & Gengar combo is smart but is once again, easily predictable. If someone can predict when you might switch your Blissy out, then they can aim to eliminate Gengar by sending an attack that they mean to be for him. No offense, it is a good strategy, but it helps when you make up one that is entirely original and your own so that your opponent wont know what beat them.
Shuckle is a great physical wall, he fits in well with most of your people but I dont think you need him and Blissy. Maybe drop the Blissy and replace it with a supporting pokemon, you seem to be all about sweepers and walls.
I like the Mamoswine though, good call, it makes a great late game phyical sweeper which you will be laking if you use physically based Dragonite as a lead.
All in all you have thought through this team well but it lacks a little depth and creativity. If you rethink some importent aspects then you will be easily able to become a great battler here on Chimchar.