This might be a stupid decision, but every so often you could achieve more by performing unreasonable actions, and what Rowan wanted to do was to kill time. He already understood ninety-nine percent of what the God King's plans were, but he had no idea what the Runes he just deciphered led to, or the ultimate plans of the Reflections of the dead Primordial of Evil and Time.
That was ultimately his enemy, a dead Primordial whose Reflections refused to die with their owner.