2000pts (1000 each) doubles planet strike local tournament

My Doubles partner is Jason a space wolf player who I imagine will take 2 dreadnoughts and various other cool stuff.

I decided to take the following army.

Inquisitor Lord
Thunderhammer, Incinerator, Holocaust
3 acolyte (bolter-flamers) 1w/carapace
3 Warrior (meltaguns)
2 Mystic
1 Familiar
Rhino
Extra armour Smoke launcher

Callidus Assassin

Fast Attack
3 Justicars + 17 Grey Knights

The Plan is to use the callidus assassin to move enemy units out of bastions while GK's swoop down to swiftly destroy them. The Inquisitor Lord will deepstrike to destroy nasty vehicles and burn enemies from their trenches.

I'll be relying on the dreadnoughts to take out anything big and tuff like soul grinders.

Hopefully I'll be able to get a grenade stratagem giving me all the grenades for my units. i.e. grey knights with frag grenades, plasma and melta.

The Fast attack Grey Knights will be the response units arriving from deep strike to fill in weak points in the defence.

Problems i'll come across are people spamming anything above average i.e. dreadnoughts etc.

Any thoughts or ideas. Or have you had any success in planet strike and like to share a few ideas?

EDIT:
Defensive List

Inquisitor Lord
Pyscannon, Thunderhammer, Holocaust
3 Warrior 1 Plasma, 1 Plasma Cannon, 1 Multi-Melta
3 Sage, 3 Mystic, 3Acolyte

Vindicare Assassin

Orbital Strike – Lance Strike
GrandMaster Incinerator, Hammerhand, Sacred Incense
Retinue 7 GKT – Incinerator, 1 TH/SS.
I plan to use the escape hatch for the Terminators. The bastions will be touching each other so the lance strike will fall on enemies outside the bastion.
The Inquisitor Lord will stop people abusing the deepstrike rule and deepstriking 5 soulgrinders next to my bastion. Otherwise they will get blown to smitherines.

Interesting looking army, sadly don't have any planet strike experience so can't say how it would work in my experience.

Looks good though you'll should snag some melta bombs for your Justies so you can do some bunka-bustin'.