I don´t realy see the point of AMM Box-launchers. I understand what you are saying re. small engagements in your game so far, but Box-Launcher AMMs simply don´t make a lot of sense to me no matter what kind of engagement you fight.
You can get more total AMMs for the same space with regular launcher + magazines and with several escorts it is very, very rare, that the limiting factor in your missile defense is the number of launch-tubes. Usually, it is the total number of AMMs available. Therefore I´d use regular launchers, say 15 with three MFCs and as much mag-space as possible.
xeryon´s point re. the box ASMs and having to return to base after a single fight anyway is valid, but I still don´t like it.
The additional range on the AMMs can come in handy against fighters/gunboats in an emergency, so I´d keep it.
I did the math. Using 37. 5HS on box AMM launchers for 250 AMMs. With 15 normal launchers, I'd only get an extra 47 missiles, and that's from one massive HTK1 mag. If they ever take internal damage they should only lose up to 3 launchers (and some other part).
The only benefit I can see from full size launchers is being able to use colliers. . . I could fit 500 (jump drive) to 1000 missiles on a collier. . . Maybe not a bad idea. I'll keep it in mind. :]
You have res-20 MFCs on your Ark Royal, but no res-20 sensor. Yes, you can engage the spoiler race at 23mkm due to your AMM sensor, but still, a range 50mkm res-20 sensor should not be prohibitive large.
Personally, I try to fit sensors (and MFCs) with quite a bit extra range into ships, so they can take advantage of new missiles later on without much of a refit (also, longer ranged MFCs counter enemy ECM quite nicely).
mmm, it'd be 5HS (the R20 active), that's 9 ASMs. My sensor tech is quite far behind. . . I should fix that. I also never intend to field the Ark Royals by themselves. They will ALWAYS have escorts. It'd just be insanely dangerous otherwise.