Well, at that point, you run into regular flak.
I think for a planetary bomber, HFA is a pretty solid choice. It might even cover the crash. xp
To get back to anti-shipping duty, so the Simurgh B Squadron will deal 2x 13 Capital, with 2 Capital for the purpose of thresholding.
Then the Prime would deal once 6-15 and 2x ... how do Cluster weapons even work.
Anyways, assuming a limited amount of attacks, wouldn't it also make sense to have a single strong hit, followed by a multitude of smaller ones to increase the chance of stacking up damage on the same facing the big hit landed on?
Though I suppose that is getting off topic - the Simurgh even offers those options.