I've read again and I think I'm with Sausana, I got the impression Guswuran, being arrogant, felt he should be the one to greet the Quya as a sort of envoy.
The immediciacy of Sujara attacking them caught me off guard, it seems clearer now that he's the aggressor.
Vippol only comes to as Sujara falls into the Horde, and wants to avenge him. But he's brought round by Cilculiccas saying not to.
As Vippol advances the Mysunsai step back to show that they had no hand in it, and a repeat of Irsulor is averted, with the Red Ghoul taking the place of Carindusu.
...right?
Though part of me thinks Sujara-nin attacked him because he had the symbol of the Mikka on his robes. While Sujara's actions as a sorcerous mercenary inspired the Mysunsai, the Mikka themselves were formed as a result of his "predations", making me think they were in opposition to him.
He sees the Compass, remembers fighting them and flips, killing Guswuran.