Question about the head of Andarna’s den

Spoilers for both Iron Flame and Onyx Storm below.

!Okay, so we find out in Onyx Storm that, as the only Irid in the Vale, Andarna is technically the head of her own den.!<

!However, in the second half of Iron Flame right before they go do squad exercises at Aretia, Andrana is arguing that she should go with them. In this argument, Tairn says he should have objected harder to Andarna’s right of benefaction. She replies that it is a good thing that he isn’t the head of her den. To which Tairn says “Codah should have known better”!<

!But Codah isn’t the head of her den, and both Tairn and Andarna know that.!<

!So why would he say that? Did Codah, as the most powerful dragon on the continent at the moment, have final say over the Empyrean?!<