I think this is something that not enough people take into consideration. No matter where you start, with maybe the exception of A where there are no or small lines for photos, the stopping messes up the average paces because people join later corrals once their line is done.
I also think another thing people often don’t take into consideration is that just because someone HAS pot doesn’t mean they are going to run that fast. Lots of reasons for this— pictures, wanting to have an easy run, etc. I have POT for the half distance but I have never ever ran the equivalent for a 10K or half at Disney.