Ok. I'm kinda new at this but here goes.
It looks like you're using a sandstorm team with the core.
First of all, if Excadrill is gonna do any spinning, it can't have choice scarf. After once, it's locked in and obvious to any seasoned player.
If you want a bulky spinner, try this set:
Excadrill @ Leftovers
Ability: Mold Breaker
EVs: 252 HP / 4 Atk / 252 SpD
Careful Nature
- Earthquake
- Iron Head
- Rapid Spin
- Stealth Rock
If you want a sandstorm sweeper, try this set:
Excadrill @ Air Balloon
Ability: Sand Rush
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Earthquake
- Iron Head
- Rock Slide
- Rapid Spin
Next, your Gallade is cool, but not as useful with T-Tar and Excadrill. Try Lucario, it works better with the sandstorm.
Lucario @
Ability: Steadfast
EVs: 4 HP / 252 Atk / 252 Spe
Serious Nature
- Close Combat
- Iron Tail/Earthquake
- ExtremeSpeed
- Swords Dance
Gliscor:
Okay as far as walls go, but Landorus is more offensive and has better stats overall, as well as sand force and sheer force.
Landorus (M) @ Leftovers
Ability: Sand Force
EVs: 252 Atk / 252 Spe
Jolly Nature
- Earthquake
- Knock Off
- U-Turn
- Stone Edge
Has Knock Off and U-Turn, as well as better stats.
Magnezone is ok as it is. With Lucario, Heatran isn't as much of a problem and HP Fire is okay.
Tyranitar, without Mega-Gallade, can use it's mega-evolution. This boosts it's stats from a total of 600 to 700. Use this set for max damage:
Tyranitar-Mega @ Tyranitarite
Ability: Sand Stream
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Dragon Dance
- Stone Edge
- Fire Punch
- Earthquake
You lose the stealth rocks, but it's so worth it.
Finally, Gengar seems somewhat useless now as a sweeper. I know that the core works well, but there are better ones out there. Something like Tentacruel works well by placing toxic spikes and taking down other pokemon. If you still prefer Gengar, he can use hex over shadow ball, especially with magnezone's thunder wave and his own toxic/will-o-wisp. Sludge wave is fine.
Well there you go. As I said before, I'm kinda new at this, so ok.