How to beat DG on Scorched earth?

Hey guys, I’m playing against Death Guard on Sunday.

Scorched Earth/ Search and Destroy/Stalwarts

I’ve never played Scorched Earth before, what should my battle plan be? I’m nervous about the burning of objectives early.

Deathwatch list is: apothecary captain in gravis Judicar (thief of secrets) Lieutenant Watchmaster (tome of ectoclade) 10 deathwatch veteran 5 deathwatch terminator 10 Fortis Kill Team 3 interceptor squad 10 indomnitor kill team 1 ballistus dreadnought 1 gladiator lancer - Armoured Hull, Icarus Rocket Pod, Ironhail Heavy Stubber, Lancer Laser Destroyer, 2x Storm Bolter 1 redemptor dreadnought - Icarus Rocket Pod, Redemptor Fist, Macro Plasma Incinerator, Onslaught Gatling Cannon, Twin Storm Bolter

DG list is: Biologus Putrifier (The droning) Foul blight spawn (shamblerot) Lord of contagion (deadly pathogen) Typhus Mortarion 10 Plague Marines 6 Deathshroud 3x20 poxwalkers 1 Rhino 3 bloatdrones with heavy blight launchers 2 brigands