I think this more or less depends on some of the choices you make.Without giving away too much, I chose to go to Circle Tower when faced with the issue regarding Conner in Redcliffe Castle. I would have eventually had to go to Circle Tower anyway to do that whole area. Had I chosen one of the other options in the Conner situation, I think it would have ended that situation much more quickly. I would still eventually have gone to Circle Tower anyhow, but through choosing to go there as a means to end the Conner situation, it simply makes doing Circle Tower part of the Arl Eamon quest line. That's what I think is going on at least, I'm honestly still on that part myself. I've been extremely impressed by the way your choices can have a huge effect on what happens. Haven't seen anything on this scale in another video game that I can think of.