I think the problem with balancing the light carronade based on that dual Pyra build is that it may hurt single carronades more than it does that particular build. Dual Barking Dogs are going to hurt whichever way you cut it in the same way dual gats or mercs will strip and shatter anything (I don't know the maths on this though). The shorter range will help inject a little more risk before that reward though.
Yeah but dual Merc/Gatling can't destroy absolutely everything in a matter of seconds, it's more about the utility the carronades have, they can destroy balloon, armor, hull, weapons, engines.. did I miss something?
That's the case when you get them in pairs at least, the burst damage is as I said, otherworldly, but yeah I can't see how you can't realy fix that easily, RoF nerf is just an example because I honestly don't see how else can it be done, unless you take out one shot as Zill said, that way a Heavy clip light carro would not be able to strip a balloon by itself and doubles would lose out a lot of damage.