I think you're almost on point with this. The change I would make is that Jaren actually transformed at the Ridge into Yor and faked his death so the name Jaren Ward wouldn't be tarnished and he could leave a beacon of hope behind as a last good act before changing into Dredgen Yor. Shin Malphur watches as Jaren Ward removes a despot leader / dictator and doesn't kill everyone - only the one guy is killed by Ward. Then they begin traveling as his deed (to purge the cities corruption) was completed. During the travels Ward understand he must leave his student behind and stages his death (mentioned above) to spur Shin Malphur onto a righteous path. If you review the Thorn cards it mentions both Dredgen Yor and Jaren Wards names in the scramble section alluding to the fact he was alive beyond the transformation on the ridge. Again like you said it is speculation and I'm only offering my perspective; doesn't mean that I'm 100% correct.