Okey dokey! I know that if Trachy battles you, he'll answer this as well. He will probably give better advice but i'll do my best.
First things first. So i see your lead is Regirock. He's a pretty good lead. Explosion and Seismic Toss are probably not the best choice for Attacking moves. Go with Earthquake and Stone Edge. I heard you have a rich history of HAX with inaccurate moves, so if you want a bit more accuracy for less power, you could go with Rock Slide instead of Stone Edge.
Swellow. Everybody said it. Switch out Steel Wing for U-Turn. I mean, what is a Rock type without Physical Bulk? I'll be changing his Nature in the Importable Copy.
I heard you replaced Torkoal for Sawk. Well, i'll give some Sawk advice. You will see this Sawk set all the time.

Sawk @ Choice Band
Trait: Mold Breaker
EVs: 252 Atk/ 252 Spd/ 4 Def
Jolly Nature (+Spd,-SAtk)
- Close Combat
- Ice Punch
- Earthquake
- Stone Edge
Duosion's turn. This guy is inferior to Kadabra. Duosion is way too slow, only working properly in a Trick Room team. I recommend Kadabra for your team:

Kadabra @ Life Orb
Trait: Magic Guard
EVs: 252 SAtk/ 252 Spd/ 4 SDef
Timid Nature (+Spd,-Atk)
- Psyshock
- Shadow Ball
- Hidden Power Fighting
- Calm Mind/ Energy Ball
Heck, this guy is faster than Duosion and has the same ability as Duosion, Magic Guard.
Golurk. I love this guy and i see you are using the Rock Polish set. Only some EV changes that you will see in the Importable Copy. All else is perfect!
Meganium. This guy was OHKO'ed in our battle. He seriously isn't benefiting your team. I suggest Lickilicky instead of him.

Lickilicky @ Leftovers
Trait: Own Tempo
EVs: 252 HP/ 144 SDef/ 112 Def
Careful Nature (+SDef,-SAtk)
- Wish
- Protect
- Heal Bell
- Dragon Tail
He's not a Taunt bait because of Dragon Tail, which phazes.
Regirock @ Leftovers
Trait: Sturdy
EVs: 252 HP/ 252 SDef / 4 Def
Careful Nature (+SDef, -SAtk)
- Stealth Rock
- Thunder Wave
- Stone Edge
- Earthquake
I'll continue the Importable Copy later.