I'm torn on this one.
On the one hand, it has some merits: being able to field-repair Frigates would be nice. I
t would also make fighters that are incongruous in size make more sense (you should see large fighters docking with a
Dachshund, it's pretty amusing).
On the other hand, it's definitely feature-creep, and it would probably introduce some additional AI complexity as well. But it would be interesting if ships could repair other ships like Carriers do, with some sort of filter for size. That might really be interesting, in terms of making battles more strategic.
I personally like using Ventures; they're tough, cheap carriers, if I need a combat-ready carrier that can survive rough conditions. For massive air forces (something we almost never see in Vanilla, but can be done readily in my mod) I buy a lot of Orions or one of the other modded-in lighter carriers or mid-grade carriers. Adding in more carrier variety was one of my biggest priorities.
I never buy Astrals, simply because I think they can't defend themselves well enough for cost. Three Orions can out-compete an Astral in terms of damage, AI-vs-AI, if set up right, and they're usually far better at defending themselves from fighters. In Vanilla, they are really hard to get and they've never been worth the effort.