I do, too - for now - but I'm not entirely committed to the idea. The first four we meet just generally seem less capable than the others; they have to work harder for simpler answers than what we see from the two confirmed Archons. Also, outside of the 7th Umbral Era storyline (though this may just be Tanaka-Era leftovers), they're just considered meddling Sharlayans. If they are Archons, we are also left to wonder who was under the robes at Hatching-tide.
Perhaps, though, it is just because they are less experienced Archons in general. Louisoix is obviously the leader, and in the Limsa storyline, Y'shtola somehow uses the echo to jump back to the exact same moment five times in her life after the Grand Companies are reformed so that they may highlight the importance of what she is explaining to you at that pre-alliance moment (If you're confused, what seems to be happening is that in-the-moment Y'shtola is urging you to commit to Urianger's plans. Then, seeminly via the Echo, another Y'shtola appears... and another... and another. It's possible that 5-days-from-now Y'shtola uses the Echo to jump back to this moment, and then 6-days-from-now Y'shtola does the same thing, and maybe 2-weeks-from-now Y'shtola... etc. all converging on the same moment.) Something tells me that takes some juice, no?
I'm going to remain uncommitted on this, for now. My true view is that the Circle of Knowing and the entire concept of archons are not anything like any of the options we have to choose from now. I think it's mostly lies. For starters, the only two people we know are archons are treated very differently. Urianger is distrusted, hunted down, and questioned - while Louisoix is trusted, accepted, and followed. Personally, I think Urianger has multiple labels, and we may know his actions better not as The Archon Urianger... but as The Paragon.
I had the same question. If he was an Archon, and this is what Archons do, where the hell did he go? Perhaps he was off doing Paragon things ><
Whatever the case, he was left out for a reason. Everyone who matters was gathered for the scene, the same as after To Kill a Raven. They remembered Urianger then, so I doubt anybody at SE was watching End of an Era and suddenly just went, "AHFOCK. WE FORGOT HIM."
Most of the releases from SE seem to indicate the same thing: it was the upset balance of aether that was to blame for the failure of the ritual. Louisoix himself alludes, during Living on a Prayer, that the amount of aether required to summon twelve deities would be astronomical and possibly in itself destructive.
By this time, most of the surplus aether of the land has spent. The primals took a bunch, which Nael then fed to Bahamut... our crystal veins in the Darkhold, Toto-rak, and Mor Dhona had a bunch, which Nael then fed to Bahamut... Nael had a bunch (we even see him personally manipulating ground veins in It Kills with Fire), which we then fed to Bahamut... and the rest of it was eaten by Atomos so hard that it tore the fabric of reality and let The Void in.
From what I understand, the archons were just the car, and we ran outta gas. Bahamut, however... had a full tank. Atomos has a respectable amount, now, too, so we'll see what role he plays in ARR.