Ground weapons are the *best* weapons for taking c3s nearby - in particular if you're attacking something on your borders. When I say ground weapons though, I'm referring to divisions featuring offensive aa batts and mid range missile batteries. They're the cheapest option, you can make the largest units with them (and thus fight most effectively with them), and they're relatively easy to use.
Air units can only be about 1/2 as large, and thus are not nearly as good these days. In PVP wars, offensive air power has become almost irrelevant, which is sad. In the recent PVP war I was involved in, my BEST offensive air wing (750 weapons) destroyed 1 interceptor (yes 1 as in ONE) before it was entirely destroyed lol. Tiny air defenses shred enormous offensive airpower with little problem, making the war engine extremely broken right now, so avoid dealing with this.
Land based cruise and conventionals are a different category altogether in terms of usage. Generally c3s aren't worth "spending" those missiles on. There are cheaper options available.
