Nurgle marines army list

As the first post with actual content, I will give you a look into my latest brainchild: the concept army list I will be working towards with my new Nurgle Chaos marines: The Legion of Rust.

This will primarily be a fluffy list created to appease father Nurgle. This will allow me to call down the favor of His Mighty Pestilential One in any battles I will fight with this list.

I had some requirements since this is a Death Guard spinoff:
- As many footsloggers as possible
- Squad sizes of multiples of 7, the holy number of his Nurgleness
- If at all possible, an army consisting of 7 squads

Now for the actual army list, keep in mind that the armament of characters is to be determined:

HQ:
Chaos lord with mark of nurgle and terminator armour. This allows me to take plague marines as troops and will fit in with the terminator squad.

Troops:
3x a squad of 7 plague marines with 2 plasma guns. These are superb as objective cappers and aren't too expensive on their own.

Elites:
6 Terminators with mark of nurgle. Together with the lord, these are the shock troops. Armament is to be decided.

Heavy support:
2x 7 havocs with 4 autocannons. This gives me some anti light tank firepower and a strength of 7 is a bonus to appease nurgle even further.

This gives me a list of 7 choices and all squads are 7 strong. The aim is to get at 1500pts.
I like to think this list isn't half bad as a recreational army even though it has some glaring shortcomings.

High av vehicles can possibly be dealt with by some terminators with combi-meltas.
Mobility is the biggest problem, but some rhinos can help with that.

This is the list I will be building towards but progress will be slow as I will only be buying new stuff as soon as the stuff I have is finished.

Any thoughts towards making this list more competitive without compromising the fluffiness are highly appreciated in the comments.