Alright so I've started doing some other testing, I am still convinced Cutters are a bit overtuned.
First my set up, I grabbed some vanilla carriers, in this case Herons and Condors.
They weren't equipped with much weaponry, the Herons had PD and Pilums, so nothing significant, the Condors had Hellfire Mirvs from CFT.
The first round of testing was a against a Paragon, from testing before Paragons usually take the most time even if youre able to beat them just because Fortress shield stalls a lot.
At 30 DP, so 3 Condors or a Heron and a Condor, they are able to beat the Paragon eventually, but it takes minutes and a lot of kiting.
At 40 DP so 2 Herons, 1 Heron and 2 Condors, or 4 Condors they pretty much dominate the Paragon with Cutters, ususally the time to kill is around a minute to a minute and a half.
Condors have the benefit of more wings per DP, while the Herons ability seems to make up for it quite a bit, keeping the time relatively even wether you use one or the other.
When deploying full DP of the Paragon, so 60, it dies. It delays a little with Fortress Shield, but that's about the only thing keeping it alive for any time, it looks like around 20 seconds, maybe 30 if it's lucky.
But it does seem like the more you spam, the stronger it becomes. In this instance, the Herons dominated the Paragon and it died after trying to get rid of the first wave of flux, with the Condor's it died before even getting to that point. I assume this is just because as you stack more and more it gets difficult for the Herons to keep up, since they pop their ability even into the Fortress shield, while the Condor pressure is consistent, so they end up performing better against the Paragon.
Next is the Onslaught, this one does really well actually, he beats the Condors at full deployment points, 40 to 40 and with the Herons it's a toss up. They sometimes kite, but somtimes the AI just gets stuck on the corner of the map lettign the Onslaught catch it, but, I would take this with a biiiiig grain of salt. The simulation Onslaught, for some reason, has 4 Flak Cannons, 2 Devestators and a Dual Flak Cannon on top, I don't know why it is specifically built to be this PD heavy with relatively little forward facing power, but needless to say, that Paragon won't be any real danger to most ships in your fleet with that loadout.
Next the Conquest, full DP so 40 just kills it no question, against 30 DP it's a bit of a toss up, 3 Condors beat it sometimes, and sometimes they don't, it depends if the Conquest gets to rush into one of them before it takes significant damage.
A Heron and Condor kill the Conquest 5/5 times, sometimes quicker sometimes slower, 2/5 the Condor died before the Conquest did but then the Heron kills it anyway, usually the fight takes under a minute depending on how much kiting happens.
So far, to me, it looks like if you have a capital ship with lots of mounts and use almost all of them exclusively for PD, then you can deal with the Cutters. Otherwise you get overwhelmed.
Speed is also a big thing, speedier capitals get gimped a lot less by the fighters in these simulations, since they can try to engage the Cruiser.
Of course, in an actual fleet battle this drawback might not be there, I might do some testing with more elaborate fleet set ups, but I am pretty convinced with the ability to project force to different areas of the battle with the fighters, they probably wouldn't do worse than in the simulation.
I attempted to fight the Astral as well, but it has 4 Bomber wings as standard, so it's not really a tough fight, even 2 Herons just with Cutters kill it quickly, so it's not worth testing much more.
Now I am going to say, of course mixing some bombers, maybe some Daggers, will increase the efficiency of killing certain things, the Onslaught for example doesn't really die to it if you do 4 Cutters 2 Daggers instead of 6 Cutters, but it can't chase you since it needs to keep it's shields up way more.
But so far, Cutters, even without the Barkentine, are very strong and can do a lot of things without needing anything else to support. As Shogouki said before, they aren't bombers, and they annihilate lightly armoured targets, but I have to disagree somewhat because they perform very well against capitals too, not just in terms of pressuring their shields while your other ships kill them, but to the point of actually being able to kill them in a lot of cases.