My problem is that while it makes sense for Jayko to become King in KK, that is not necessarily true for the KotOS Series. You see Jayko is an important character of KK. He is a protagonist and plays a major role in the turn of events. However, in KotOS he is just a side character helping the major characters. He hasn't even been as emphasised as the other KK Knights, who have gotten some more attention in the latest chapters. Secondly, Matthias has a daughter in KotOS. While that can be bypassed as you have said, it is still odd not to make her the queen. There was also something about Book 3, but I suppose it doesn't matter that much; the result can be that Jayko becomes the King, anyway.
Also, hasn't the age of PCs just returned? :P