Legendary Pokémon

I'm not new to pokemon but i'm not one to strategize(sp)

well my question is whats so bad about using a team of sweepers?

my team right now is

Tyranitar (Hardy) (trying to find Adament!)
Attack - 320
Def - 259
SP. Att. - 237
Sp. Def. - 256
Speed - 176
Moves: Crunch, Stone edge, Earthquake, Thrash

arcanine(quiet)
Attack - 284
Defense - 200
SP. Att. - 271
Sp. Def. - 193
Speed - 202
moves: Flamethrower, Thunderfang, Overheat, ExtremeSpeed

electivire(mild)
Attack - 286
Defense - 169
SP. Att. - 268
Sp. Def. - 225
Speed - 231
moves: Thunder, Thunderbolt, Focus Blast, and ?(need a move)

swampert(Serious)
Attack - 245
Defense - 232
SP. Att. - 222
Sp. Def. - 235
Speed - 164
Moves: Muddy water, Focus Blast, Blizzard(might replace with Icebeam), Earthquake

garchomp(mild)
Attack - 279
Defense - 225
SP. Att. - 244
Sp. Def. - 223
Speed - 246
Moves: Dragon Claw, Draco Meteor, Crunch, Earthquake

metagross(Docile)
Attack -304
Defense - 311
SP. Att. - 231
Sp. Def. - 219
Speed - 179
Moves: Psychic, Meteor Mash, Earthquake, (need move)
all lv. 100

MIGHT PUT THIS ONE IN INSTEAD!
Gengar(mild)
Attack - 184
Defense - 162
Sp. Att - 352
Sp. Def. 198
Speed - 267
Moves: Hypnosis, Nightmare, Shadow punch, Dream eater

i hear its not smart to use all these pokemon, but why?

just need an explination and some advice if you guys want.

thanks in advance!!

Any move advise is helpful because i just dnt know what to put on which pokemon.

Actually, a team full of sweepers may work on D/P. The general problem is that if your opponent is using Sweepers stronger than yours or if he is using Tanks, he will propably defeat you. The Pokemon you use are best used as physical sweepers. So someone with physical Walls or Pokemon with will-o-wisp will truble you a lot. Furthermore, you should provide us with more information like the attacks and natures of your Pokemon, because I can't tell if they are good or not without these information. And if you are using Electivire, try adding a Pokemon that will lure you opponetnt in using an Electric Attack. Gyarados would be a good choice.

Also, try to tell us about the final stage of you training ( of your poke of course )
If you are going to train a tyranitar you don't have to say the nature of the fail egg just the good one. F.e You should say directly adamant nature for your Tyranitar. Except of what Blue said, something that will not favour your variety of attacks is that these guys are all ph.sweepers so you are gonna learn to all of them earthquake and maybe sd. If you just place some tanks or walls with speciality in sp.att you'll probably have the chance to attack with your tanks/walls too.

P.S. I don't know if i made myself clear.

Actually if you like these Pokemon you can use them. Swampert and Metagross can be fine tanks and Metagross can be a surprisingly good special sweeper as well. Furthermore I think you should change most of your Pokemons Natures. The dont'n help them at all. Take your time and see some guides on the Main Site as well as around the net. You will find a lot of useful things. Then you can ask here for more information.

I see why people say it's not smart to use all those Pokemon. It's not the fact that an all-offensive team is bad (it's the main style I play, just ask GeorgeSlayer,) it's the fact that most of them are weak Ground, and you have no Pokemon with Levitate, the Flying type, or the Grass type. Your team would be better off if you threw something like Azelf, Gengar (:]), or Celebi there.

If you really want us to help you to the fullest, amending your post with the moves of each Pokemon will be nice. Good Luck.