Because cost, complexity but also effectiveness is driven up by the sensor suite and at that point having a supersonic platform not only allows it to more effectively fly in defensive ways, thus increasing the survivability of the aircraft and justifying the additional cost of enhanced capability.
That is true, and I agree that if you've already dropped money into high end sensor suites, then you might as well make it more survivable. But the point I'm trying to make here was that being subsonic by itself isn't unworkable or terribly disadvantaged in a defensive air to air fight.
No, it also makes it a more effective launch platform for potent air to air missiles, high speed and high altitude lend themselves to more energetic launches. And being a capable launcher automatically puts the adversary into a defensive posture, having to avoid an incoming missile or risk getting shot down. This in turn along enhances survivability and justification of capability and cost increase (to a certain level).
I don't disagree with any of the points your making (except the shot down in droves part, which I think is an underestimation of networked subsonic drones).
On the surface level it's speed and altitude that gets the first shot advantage. However, in order for you to achieve what you described, you must ensure that between the time that you launch and when the missile forces the enemy defensive, your enemy is completely unable to respond in kind against any of your own units. Launching on an adversary doesn't translate to adversaries taking immediate, wholesale defensive posture and becoming totally unable to respond - and especially not so when the shooter doesn't have to be the sensor.
When you have numbers with capable enough sensors (even if they still aren't as good as your high end CCAs), you have tactics to employ that take advantage of your greater formation depth and more angles to engage from. You can also expect a substantial amount of fighting between LO platforms to take place well within range of an AAM's max or optimal range shot at mach 1, 20 - 30k ft -- in addition to longer ranged, targeted or shaping shots. That means even if your opponent flies subsonic and shoots at lower speeds, their missile can still reach you force you defensive. With AEWC support, sure - you shoot at much further ranges, but the opponent can simply choose to evade early and use their formation depth to continue to push you. The formation depth, azimuth advantage and missile capacity afforded by greater numbers will try to force you flying low and turning evasively while they close the distance. As distances close, altitudes drop and timelines get compressed, you are less likely to even be able to use any speed advantage before being forced to shoot back and defend. Sure - these conditions aren't always achievable, but that means that the more capable, less numerous force will be choosing their fights wisely instead of a cross the board turkey shoot.
The point I'm trying to make here isn't that subsonic CCAs are the best thing for the job but rather that even with subsonic CCAs, there are things that you can do with greater numbers to negate the advantage of a more capable but less numerous opponents. Their viability in an engagement comes down to a problem of tactics, or more finely, whether numbers, angles, magazine depth and formation depth can out compete speed and detection distance. After all isn't that what the entire CCA paradigm is trying to do against manned fighters too?
@bring_it_on summarized it in a much better and less verbose way than I have, but that's essentially what I'm saying - just looking at the plane itself really doesn't say much and using individual capability to preclude the viability of less capable CCAs for an air to air role is premature.
The cost factor is hard to pin down, because even if you field cheaper and less capable drones, when they are loaded with expensive missiles and shot down in droves you are still bleeding massive amounts of money without getting much out of it in return. There is a reason that Reapers, Orions and Wing Loongs aren't flying around in flocks armed with AMRAAMs, R-77s or PL-15s. They're simply unsuitable for air combat, there's a reason the subsonic fighter jet essentially died out, with even more strike oriented aircraft like the F-35 retaining supersonic flight. It's also what stopped ideas of arming subsonic bombers with air to air missiles, together with cost and airframe sacrifices.
I think there's a difference here between reaper type subsonic aircraft and a high subsonic aircraft. First off - none of the reaper type aircraft are in any way shape or form LO. Secondly, these aircraft's top speed aren't even half as fast as a high subsonic CCA. They neither have the speed nore maneuverability to evade missiles at any range and may as well as be considered non-maneuvering targets. Many high sub-sonic CCAs are both much faster, much less observable and possess greater maneuverability.
Point being, the first Increment of CCAs isn't the ideal platform for air to air combat, but they are still very useful for various other reasons.
Absolutely agreed.
Kizilelma, Airbus' Wingman, Vectis, Okhotnik and other high end UCAVs in development or proposed show a clear interest in more resilient, more capable and more expensive drones that are slowly approaching fighter like performance in an unmanned package. So it's not about cheap and numerous or more costly and less numerous, it's about the ratio of these in relation to each other and other manned and unmanned assets, it's about how to make them work together, their roles. Because both will coexist no matter what, because one can't effectively substitute the other. So there's no need to be upset over an assumed lack of capability in the chosen increment 1 CCAs, or presumed overcomplexity of Vectis and similar drones. Which is something I've observed here and elsewhere, with advocates for either side of the discussion disregarding the merits and quite frankly the need of the other.
I don't personally find the subsonic or less capable part upsetting (anymore), which is why I'm making the argument for workable subsonic air to air CCAs in the first place. I also recognize that less capable CCAs would be working in concert with more capable ones and China seems to be doing both.
The reason I have not fully entertained the idea of a supersonic CCA for the US here is because whether its what top companies are offering or the language we've heard from the services, there isn't any interest (or mention) of higher speeds for CCAs - even when there is discussion about higher capability. Instead, all the new offerings of more capable CCA increments thus far apparently used their capability margin for more LO and more capable sensors instead.