Slowking (M) @ Leftovers
Amnesia
Icy Wind
Psychic
Surf
~ I used to use Belly Drum/Earthquake/Rest/Fire Blast to some sucess, it's like a miniature snorlax with a metric ton of spdef and no fugly fighting weakness which in the end works out well, plenty of paralysis support helped. On your set: ditch ichy wind for fire blast if you must use Amnesia (it does nothing for your offensive stats).
Electabuzz (M) @ Leftovers
Fire Punch
Ice Punch
Psychic
Thunderbolt
~ Cross Chop > Fire Punch. The only thing fire punch helps with is steel types but Skarm is electric weak and steelix is going to own buzz with or without fire punch. Psychic can be dropped for HP Grass if your into owning golem/rhydon.
Arcanine (M) @ Leftovers
Body Slam
Extremespeed
Flamethrower
Hidden Power [Electric]
~ Why have Body Slam and Extreme Speed on the same set, it's completely pointless, HP Electric is also weaksauce with arcanine spatk. Curse, Extreme Speed, Hyper Beam and Fire Blast a good setup in my experience, Hyper Beam is a sick surprise tactic for when blissey or something similar appears.
Golem (M) @ Berry Juice
Earthquake
Return
Rock Slide
Sandstorm
~ Roar over Return, Explosion over Sandstorm, that way you can pseudo-haze and do the KABOOM which can own if you think something is coming your way.
Donphan (M) @ Leftovers
Ancientpower
Earthquake
Horn Attack
Rapid Spin
~ Horn Attack? Weak. Rapid Spin is pretty unescessary especially on a team with very little recovery methods and no heal bell, you wont outstall a spikes user anyway. Ancient Power and Earthquake are ok, but I don't see the need for this guy in your team - he opens up a sickening Starmie Weakness.
Dragonite (M) @ Leftovers
Dynamicpunch
Flamethrower
Ice Beam
Wing Attack
~ Drop Wing Attack for Body Slam I'd say, also consider ditching Ice Beam for Thunderbolt if you DO NOT do that.
Overall: this team has all the hallmarks of a team of someone learning netbattle, no paralysis support, not enough status afflicting moves, few stat ups, and a few too many ground types. It's got plenty of sweeping power but lacks haze/pseudo-haze, and status effects.
In order to improve your team, I'd advise dropping some of the sweepers (Donphan and Arcanine spring to mind) in order to get some form of Paralysis support (Exeggutor with stun spore, Slowbro with thunder wave, etc) and possibly consider in getting some sort of special tank (blissey and snorlax work very well).
The reason I say this is that on netbattle very few people will try to use sheer power, most GSCer's tend to use a mix of stalling and sweeping using stat ups like Curse (Snorlax with Curse is a big favourite) and it takes ALOT to punch through a standard team.