I'm not sure I'd describe "going from 2 capitals to 3, with the new one being tailor-made for the encounter" as "capital spam" (I mean, who's to say what would happen if you replaced one of those with a pair of capable cruisers?), but aside from that: very much *thumbs up*!
As I generally only run two capitals, maybe 3 if one is a battlecruiser, this is cap spam to me. Especially two very meta capitals, including a juiced flagship.
I've been using cruisers pretty much the entire playthrough, mostly high tech stuff. Anubis, Aurora, Fury. No combination of any cruiser I've fielded could handle as much as the Mk1. Not even close.
I guess what I'm trying to say is that it seems like the second you go off the ships that are tailor made for the content, it gets considerably more challenging. If you move away from Paragon, Onslaught, Mk1, etc, it's a completely different game. I'm not sure that's a good thing or not. Maybe it is?
Spoiler
I've had a pretty good time with a bunch of Eagles vs Threat, of all things. Like 8 of them or something, plus a few assorted smaller ships, and an Odyssey flagship, which I just find fun. The Eagles end up dominating all along the front and basically surrounding the Fabricators at some point. Personal piloting on the Odyssey definitely makes some amount of difference, though I've also tried it on autopilot and it works. Didn't try it vs a "many Hives and Overseers" fleet, though; probably should at some point!
You definitely should see how it plays out. I'd love to see your experiences. Overseers are the most impactful ships in the fight.