My reasoning:
(I know you play MMS).
I take weapon batteries on the Dragonship because more batteries at once is better regarding blastmarkers.
But 3 Pulsars is not to be sniffed at.
I take Pulsars on the Wraithships because that adds to the Dragonships.
I take launch bays on the Dragonship because I need one RO to have 4 AC available.
I put torps on the Wraithships because I am no AC spammerd and torps are cool anyway.
But if you have 3 Wraithships and 1 Dragonship you can certainly make the third Wraithship a battery/launch bay vessel.
Ghostships (mms) are fun too. All direct weaponry.