I feel like one of us is remembering the story wrong ... or we're both doing the same thing -- that is, giving our take on what we think is happening. But you seem to be taking it further than the game gives information about, unless I've completely forgot some in-game explanation.
I don't remember any kind of detail on how the dreamer's power works or how he writes the scripts. Just that he dreams about alternate realities with fascinating stories and he turns them into movies (that happen to closely match AVNs many people that play this game like). I don't remember how much he sees, how long it takes for him to publish a script, what the stories even are (other than the little we got about The Assistant). But it seems clear he's not seeing 1:1 timelines ... whether he sees an entire story overnight, over a week, over a month ... it'd have to take less time to see than actual time passing in the game's world. For all we know, he gets a full world dump every night and he has to spend his days sorting through the information to find the stories he makes (which would imply he doesn't forget much, if anything).
As for what details are wrong, have we got any details about any of the movies? If you're talking about the fact that the characters on the posters don't match the games they're from, that's 'cause the posters are of the actors playing the parts (something I found very disturbing at first, I can tell you.)
Anyway, I may go find that scene and replay it to see if there's something I forgot (very likely, even if I'm right. I definitely wouldn't remember much about the dreams if I had that ability ... and my current brain), but for now I think I've satisfied the itch your little word salad created in me. It was a fun dive.
