That is a good question!
Since I named the thread “brainstorm”, my initial thought was no. So only the Phoenix and the Leviathan would be the capitals, shooting xl missiles.
The CIWS was intended for all carriers, faxes, dreads, supers and titans.
Since dreads can fit haw guns or the rapid jesus launcher, I thought a frigate defense wouldn’t be required.
Citadels already have an anti-missile defense, just with a different name.
Well imagine flying a thanatos. Your align time is 30+ seconds or so.
Fitting a capital afterburner propels you into warp in half the time, in my opinion it would be a good idea to have one of those at least with you in your carrier.