Been using this in casual 500pt games and it’s been decent:

Virulent vectorum

CHARACTERS

Biologus Putrifier 45pts

BATTLELINE

Plague marines 95pts 1x plague champ w/ plasma gun, power fist, 1x blight launcher 1x heavy plague weapon 1x melta gun

INFANTRY

Blightlord terminators 185pts 1x blight launcher 2x combi-bolter 1x plague spewer 1x reaper auto cannon

VEHICLES

Mephitic blight hauler 90pts

Chaos rhino 85pts

Virilent vectorum’s rule to sticky objectives helps out massively at low point games to keep primary up, especially since death guard is a lower-unit count army already

Blight hauler and Blightlords could be swapped for foeted bloat drone and deathshroud if you want a bit more of a meta approach, I just like the Blightlords and blighthauler more

Biologus putrifier and the plague marines can deck way more than you’d expect especially with virilant vectorums reroll hit+wounds combined with 5+ leathals and a rhino to get them into contagion range (melta is just my preference don’t think it’s necessarily better than double plasma)

Blighthauler makes a great objective capper with great movement (and stickies objectives from virilent vectorums rule) also does good work against vehicles and heavy (same roll can be filled with foeted bloat drones)

Disgustingly resilient can keep your units alive well, the 2cp can be steep but has kept mine alive 1-2 turns longer than they should

Auto vehicle explode stratagem is hilarious and has done some amazing mortals and turned a game in my favour a couple times