Archeops
Acrobatics
Earthquake
Rock Slide
Quick Attack
Samurott
Megahorn
Aqua Jet
Waterfall / Scald
Swords Dance / Work Up
Eelektross
Wild Charge / Thunderbolt
Flamethrower
Grass Knot / Acid Spray
Hidden Power [ICE] / Grass Knot / Flash Cannon / Wild Charge
Hydreigon
Draco Meteor
Surf
Dark Pulse
Flamethrower
Volcarona
Quiver Dance
Bug Buzz
Fiery Dance
Hurricane / Psychic / Hidden Power
Krookodile
Earthquake
Crunch
Stone Edge
Bulk Up
Unfortunately, Archeops or Krookodile has to go. They both fulfill similar roles, only one is stronger while the other is more defensive. Use Acrobatics for sure because it's basically Archeops' signature move. Equip a Flying Gem and you have a bP 247.5 Acrobatics on Archeops' godly ATK stat. Quick Attack is a good attack, since Archeops doesn't learn anything that he can use that will do more damage than Acrobatics / Rock Slide.
Samurott has okay stats. Make them better with Swords Dance. His only really unique move is Megahorn, so give him that. You can use Work Up if you want to use Scald or Surf as well. Aqua Jet is a good move for Samurott.
Eelektross has a really varied movepool, which is good, but also sort of repetitive. Use his Special moves over Physical, except with Wild Charge, which will hit everything hard anyway. If you run Acid Spray, then you could use Thunderbolt, but Wild Charge will prevent him from getting walled by things with Light Screen, Calm Mind, or Amnesia. You really do want Hidden Power [ICE], but if you can't get it, you could settle for something else too.
Use Hydreigon's Special stat. Draco Meteor for a quick kill, then switch out to avoid the repercussions. Dark Pulse on most anything else. Flamethrower / Surf provide good coverage. You don't want to be using Dragon Pulse because it doesn't hit super effective on anything but Dragons. Anywhere you would use Dragon Pulse can be replaced by Dark Pulse. Draco Meteor can be used on stronger foes. Honestly, mine has Flash Cannon, but that's only because its my favorite move.
Psychic is okay on Volcarona, but Psychic is a pretty bad attack anyway. Hurricane doesn't do much for Volcarona either, whose other moves take care of the same weaknesses. Since most Fighting-types know Stone Edge / Rock Slide, Psychic might not be the best choice to deal with them. Bug Buzz and Fiery Dance are usually sufficient attacks anyway. Fiery Dance over Flamethrower / Heat Wave because it's worth it (and Quiver Dance will make up for the power loss).
Krookodile's job is to use Crunch / Earthquake... Something many other Pokemon already do. Bulk Up is there to help him out with his stats. Stone Edge is basically a given on most Pokemon that learn Earthquake, but Outrage is usable too (but doesn't offer much in coverage).
OK, I like doing Unova-only teams and making the best out of them. So, here's what I would do with your team:
Hydregion, knows crunch, hyper voice, Rock Slide, dragon pulse
Volcarona, knows heat wave, quiver dance, bug buzz, Psychic
Krookodile, knowing earthquake, foul play, outrage, and Shadow Claw
Archeops should know Fly because it's more powerful and can still take advantage of high attack stat and STAB.
Samurott should know Megahorn because having more than 2 offensive moves of the same type makes him less reliable in various situations. Megahorn lets him defend against Dark and Psychic.
Eelektross, once again, shouldn't know more than 2 offensive moves of the same type. Also, Zap Cannon and Thunder aren't very reliable as far as accuracy. The chosen moves give him defenses against more types.
On Hydreigon, I personally believe that Draco Meteor is overrated because it sharply reduces the Special Attack stat. This would leave Hydreigon with only Crunch as a reliable move. Therefore, Rock Slide is a better move to have in that place.
On Volcarona, I replaced Fire Blast with Psychic because 1. None of your team knows any Psychic-type moves, and 2. Fire Blast is only 20 points more powerful than Heat Wave, and has only 5 PP. You're better off with Heat Wave. You could even replace that with Flamethrower.
Finally, with Krookodile, Focus Blast is a special move, and Krookodile has low Special Attack, but high Attack. Therefore, Shadow Claw. You also don't have anyone else with Ghost-type moves.
Since when was Fly more powerful than Acrobatics? >_>
Also Dragon-type moves suck.
