Okay, there may be a few holes.
Tyranitar and Dragonite will tsay for sure, and I may sub out Metagross for someone else. But most of my pkmn would have earthquake, which takes out electivire
Yeah, and there goes your buffeter for Earthquake. :\ And Electivire was merely an example. There are many other Physical Sweeper Pokemon out there that can learn moves like Ice Punch and Earthquake. Take Medicham for example.
Dragonite is a flying type that can easily take out Medicham. And pkmn like that don't get STAB, which reduces the effectiveness of them.
And you said where's the fun in that a few posts ago... this team will be at the end of the game. I don't know what my team will be for the main storyline e.g. 8 gyms + elite four, but it may look like this:
Empoleon
Staraptor
Luxray
Leafeon(can you get this pre elite four?)
Rapidash
HM slave
I've got:water, steel, normal, flying, lightning, grass, and fire. plus and HM slave to put in to use a quick revive/potion of some sort. I normally don't need too many pkmn while I go through the journey. In fact, I played my bro's fire red version using only Blastoise and an HM slave. By the time I got to the elite four Blastoise was in the high 70s.
As I've already said before, that team is post elite four/main storyline. In the quote above is my plan for a team pre elite four(as in form the beginning).