Hey, great team so far! I've been competitive battling for a couple of years now, and this is one of the most balanced teams I've seen so far on PokemonDB, with at least one Pokemon 1/2x effectiveness defending against every type.
I agree with fondant, a Tentacruel is a good team member to replace a Wailord with. I typically have one myself and it's invaluable as it catches people off-guard. I don't have a particular set that I run all the time, and I like to experiment with different move sets, but try this one:
Tentacruel @ Black Sludge
Ability: Liquid Ooze
EVs: 252 HP, 220 Def, 36 Spe
Nature: Modest
- Rapid Spin
- Scald
- Acid Spray/Sludge Bomb
- Knock Off/Protect
You should definitely have Black Sludge on it, Rapid Spin, and Scald. I wouldn't have both Scald and Toxic together. Instead, try Acid Spray or Sludge Bomb for the third moveslot and to get a Poison type move. For the last moveslot, I would have Knock Off or Protect.
Also, I don't use Chansey myself. I use Blissey. I know that everyone says that EvioliteChansey is way better, I prefer the higher HP and SpAtk stats myself. But if you're set on a Chansey, it should probably be running Wish for support.
As for Zapdos... it doesn't really do much for your team, other than Ice type coverage. Try a different Electric Pokemon. Personally, I like using Luxray, but if that's not your cup of tea, try a Magnezone instead. Luxray is a better attacker, but Magnezone is a better special attacker. The set I use for Luxray is this one:
Luxray @ Choice Scarf
Ability: Guts
EVs: 4 HP / 252 Atk / 252 Spe
Naive Nature
- Wild Charge
- Ice Fang
- Superpower
- Volt Switch/Electric Terrain
I use Electric Terrain if I'm running more than one Electric Pokemon or other Pokemon with Electric moves. If I have more than one Elec. Pokemon, sometimes I'll switch out Wild Charge for Electric Terrain. I set up ET, Volt Switch, then switch to another Electric Pokemon.
For Magnezone, pretty much anything goes, as long as it has Flash Cannon and Thunderbolt, two of its best moves.
Hope I helped and good luck!
-disdestroyer