My second Troop Choice. A 5 man Tactical support squad with Flamers equipped with chem-munitions.
My current ratio for armour variants in a squad is 3x mk3 1x mk2 and 1x mk4 in every 5 men. This is down to the Legions love of the mk3 plate due to its resilience and sturdiness.
First time these fired I got one gets hot roll and killed a Legionnaire, but it killed far more enemy Legionnaires. Flamers are pretty impressive with the shred special rule. A decent Death Guard trait in my opinion.
5 Autocannons next then onto the Medusa crew.