3 ravagers, 3 reapers

If I wanted to make a list with 3 ravagers and 3 reapers, which kabal (or cult or coven) would you suggest for the best obsession and overall synergy? Having that much heavy fire would push me to use flayed skull gunboats or venoms, but If I take 2 black hearts for the rav/reapers, I won't be able to use a flayed skull because of the 3-archon max rule. Maybe Obsidian rose and use the gained ranged to maximise the rapid fire mode of my kabalites warrior?

You can fit three Ravagers and three Reapers into a single Black Heart Spearhead, which would allow you to take a Flayed Skull Battalion if you wanted.

Honestly if you can field 3 Reapers I think you should field them as either part of your Black Heart Spearhead or as a Dark Creed Spearhead.

If you're already running 3 Archons and don't want to get into Drazhar territory then there is totally a Coven that synergizes well with the Reaper.

Last but not least is the Cult of Strife for their Stratagem.

Ultimately, I think you should run the Reapers as part of a Cult or Coven detachment and open up some more of the codex to you.

Coven of the Dark Creed gives you the option to use An Esoteric Kill Delivered from Afar with a Reaper, which seems incredibly nasty. Dropping to 5+ invuln makes grots/talos a lot worse and you have a ton of points sunk into the tanks, so I'l probably run it as Spearhead to accompany a Kabal battalion (containing Ravagers) and try to get another battalion in there somewhere for CP fuel.

All this might be too cute though compared to just piling everything into the same Black Heart Detachment to get the benefit of Archon reroll aura and Writ.

Unless I specifically had 3 Reaper models I want to use, I'd probably rather bring a bunch of RWJFs (dissies or lances).