It's not only c47's, lvts and m3's that can supply a base. The key, in this case, is probably killing either the convoy of supply trucks or the tugboat with supply barges that are towed in from the sea - whichever the base receives.
If you really want to keep the base 'down' then killing those is probably a must. Problem is they seem worth near zero points. Why would anyone fly to an enemy base and use up their precious amo, which they were saving to vulch, on the programs 'auto supply vehicles.'
How does this stuff go? Suppose that every supply convoy is entirely destroyed, will the base repair at all? How much does destroying one truck or barge slow the re-upping of a base, or a component of a base?
Possible solution, knowledge of how trucks/barges affect stuff, and making them worth more points! Achievement?