'kay, I'll look at it from 2 fronts:
1) Fluff: Pretty on the nose. The apothecaries run with the tacticals I assume (SUPER fluffy and pretty damn strong). Don't overly worry about having everything in multiples of 7, though the most fluffed out "unit" of
DG is a 20-man tactical squad w/ apothecary-sergeant, extra
CCWs, and vox/vexillia. As you pointed out:
DG don't like hard to maintain weaponry like volkite or plasma.
2) Crunch: If you're running the deredeo w/ plasma, swap the missiles for the invuln buff and run him next to your Deathshroud. Don't bother with Armoured ceramite on the laser vindicator (
AC should only be used for things that you KNOW will generally be in melta range as it's way to expensive to put on everything.) You will want to run the laser vindicator and the regular vindicator as 2 separate squadrons as one is super
AT and the other isn't. Maybe running that regular vindicator as a Medusa for the time being? Another great upgrade is giving vindicators machine spirit so they can move a full 12" and still fire the main gun. It's also a great Idea to give your sergeants/ apothecaries artificer armour to buff up the durability of your blob squads. rask is cheap, but running him with volkite is wasting his buffs. we're that a
HS squad or a squad with more high strength shots, it would make sense, but at the moment you're giving Culverines tank hunter, which won't do all that much.
Maybe something like this?
HQ
Generic praetor (kitted out for
CC he'll be more expensive, but hit MUCH harder)
Deathshroud Termiantor Squad (they are a plain
HQ choice as well, remember)
TROOPS
2 20-man tactical squads w/ extra
CCW, vox, vexillia & Sergeant w/ artificer
6-man Support squad (Volkite, unless you've got something you like better?)
ELITES
2 Apothecaries w/ Artificer, Augury Scanner, and rad.
HEAVY SUPPORT
Deredeo w/ plasma and pavias (or however you spell it

)
2 Legion Medusas
1 laser Destroyer Vindicator w/ machine spirit