Yeah I agree the bats would have seen everything, or close to it, that was happening in Jetstone. I was thinking of the entire side, though. TV wouldn't have much, if any, intel on the rest of GK, unless they have directly observed it or indirectly been told what was going on. They might know most or all of the Archons in the city were lost, but not ALL of GK's Archons, everywhere. Same with the dwagons, unless someone gets close enough to count them, they won't know how many GK has left. And those are huge differences, "all archons lost in the city" is "okay, neat" but not much else - "all archons lost on the side" is "okay, actionable intelligence, time to step up the spying and foolamancy"
This is all "unless someone told them" of course - but from what we've seen, allies don't seem to share a lot of intel. Don didn't tell Jillian about Ansom being decrypted which he learned from Queen Bea, for example, Charlie had to go tell her. (Edit: I could be mis-remembering the order these events happened in.) Allies do share troops, but even that seems more like "here's a few thousand troops and some warlords, send whatever survives back home and let me know how it goes"
I do also agree that Jillian kept this from being a complete massacre for Jetstone. Her stalling tactic, and then Kingworld which she helped enable by ferrying the turnamancer to the battle, is the reason why Jetstone survived this turn at all. Jillian then left because she thought the battle was in the bag. Flying units with no move trapped in a city hex full of archers and casters? Don't let a corpse fall on your head and you'll be fine, right?
Her chief warlord couldn't even imagine how Jetstone could lose that.