I think JC has already set on Rowan's fate in the earlier years. That's why they don't bother including Rowan in any quest or activity just because they're lazy to make the effort on their story/animation. Rowan is gonna die anyway, JC doesn't bother with a dead character. Waste of time and resources.
About Ben, all blame should be put to whoever wrote the script. Yes, he was already pretty annoying in the earlier years. But, after the incident where he was revealed to be the wizard in red robe, he was showing some kind of development in Y5. The building of it was acceptable. But no. The writer decided to turn Ben's character 180 degree in Y6 because he was completely shocked that he was abandoned by Rakepick. In this particular scene, Ben only saw himself while actually it isn't just him. MC, Bill, Merula, Charlie/Penny were also abandoned by Rakepick. No JC, that is not how you write a trauma.