"The Stand" & "The Dark Tower" Ideas and Thoughts. [MAJOR SPOILERS]

I was wondering what you guys thought about Randall Flagg's appearance in "Wasteland" & "Wizard & Glass". To start, I know that he was Walter O' Dim and has appeared since the beginning. However, I am referring specifically to his incarnation of Flagg. More specifically, his appearance in the Topeka that Blaine the Mono left Roland and Co. in. Do you think Roland & Company actually appear in "The Stand's" timeline? Is Roland's encounter with RF the stories happening in tandem with the Mother Abigale and the other survivors adventures?

I myself like to think so. I like to think that at some point during "The Stand" RF was walking the hidden highways, before he made it to Vegas--or maybe after he took control of Vegas--old Randall was taking the time to encounter Roland and his friends.

But I digress. What do you guys think?