[Dragaera] Court Wizard crack? (Minor Tiassa spoilers)

[Jon Lincicum]

Tiassa Spoilers. 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 

The middle section of /Tiassa/ introduces us to the heretofore unseen character Kosadr. We are informed that this character is the Court Wizard for Zerika IV. 

At one point in dialogue, Kosadr claims that he "has held his post for 20 years". 

However, the events in the section take place approximately 1 year after those depicted in /Issola/. In that story, Morrolan makes a joke about Zerika sending the "Court Wizard" to assist in the battle against the Jenoine, where he is referring to himself as the current holder of that position. 

On the face of it, this appears to be inconsistent with Kosadr holding the same post for 20 years prior. (Especially since Vlad indicates that prior to Morrolan, it had been Sethra the Younger who had held the post.) 

Any ideas? 

Majikjon