I haven't used anything up until now on the Arc Royal.
you "could" just run an escort AA ships (toss on a Sonar Sailor on board to help you spot incoming subs), then use your HH as needed.
however, I've also seen, and used your gun slots to hold support sailors, especially repairmen or restorers, or to hold other pilots you're training up until you get more support slots to house them in on higher level cvs.