Ehh, not really sure what your getting at. As if they really wanted to Just kill them. Why would they even bother talking to the team? If anything they just wanted to take them into custody. As if you think about it, Brand, sadia and roko Kinda did a very very bad thing. Stealing the eye, you know the eye that if united can End all existence. Granted this entire story has been about getting said eye back. But come on they don't know that it rolled off the edge and fell into the ocean. So the only assumption they have is Sadia and her friends stole it. Why, who actual knows, all they know is Sadia ran off with some unknown volcano dragon and his shapeshifting friend.
So ya, they kinda have a reason to ambush her instead of Politely asking her to Return the stone. Combine this with the fact that she is a Quetz being aided by a Volcano dragon and his Kitsune companion. Not surprised that they would come in armed to the teeth. As how else would they arrest her for Stealing the World ending Micguffin? As in the end Aves are just birds. Dragons on the other hands are offspring of gods.
Also lastly is the fact that Roko was the one who initiated hostilities. Roko drew the first blood in this encounter. For all you know if they Just told what exactly happened. And how this entire thing was a big Mistake. Their is a possibility that the entire conflict could have been avoided. Slim one but hey better then nothing. As let be honest hear. the Repercussions of rokos action hear will Most diffidently lead them to be hunted down. As the they know what happened. They know sadia swapped bodies. They know that she has the eye or at least knows where it is. And worse, she has possibly(we don't know if anyone is dead yet) killed members of the Kingdoms court. So now she gets to be hunted down By anyone associated with the Quetz...
Side note, just feel like pointing out this hypocrisy. As if brand is correct and they are slaves. What did he just accomplish hear? He just Possibly fried a bunch of slaves. Like what aves are wroth Saving and what aves are not?