Personally, I hate Chancy stallers, but if you have Chancy, I will not hate. But I would use Shuckle instead of Ferrothorn for traps;
Shuckle @ Chesto Berry
Ability: Gluttony
EVs: 252 Def / 252 SpD / 4 HP
nature Nature
- Sticky Web
- Stealth Rocks
- Toxic/Rock Slide
- Rest
This will further better your traps game because of Shuckle's defenses. Switch to Chancy if Shuckle is in danger; it is only in danger if you have already rested once(Chesto eaten) and very low, a.e. don't want to risk another rest. Chancy will bulk hits until all of your traps are set. After that, it's game to your power houses.
I do have a problem with your Lando-T. Sash on a Lando doesn't work in my opinion because there is nothing that can one shot it without taking an Earthquake or weak to Greninja and Medicham. Using Shuckle would also free up a slot on Lando-T. Mago Berry heals about half when your Health is 25% or lower. Psychic Seed gives Lando-T 1.5 SpD boost for Psychic Terrain(Lele)
Landorus-Therian @ Mago Berry/Psychic Seed
Ability: Intimidate
EVs: 252 Def / 252 Atk / 4 Spe
Jolly Nature
- Earthquake
- Knock Off
- Rock Slide
- Swords Dance/Explosion
With Medicham, I prefer Drain Punch(75 power) over High Jump Kick. It is more powerful than High Jump Kick(130 Power), but Drain Punch lets you heal.
I noticed that you don't have a Rapid Spinner, although your mons aren't affected by Stealth Rocks too much.
Good Luck!
