Peter Pan's Flight hourly capacity is around 1,100 riders per hour. (Source:
http://touringplans.com/magic-kingdom/fastpass)
I believe a few of our respected members including
@danlb_2000 had done the math earlier and 7DMT could average 1200 riders per hour (if dispatch is 60 sec) 1600 riders per hour (if dispatch is 45 sec) etc.
This debunks your Peter Pan's Flight is "ONE-THIRD" the hourly capacity of 7DMT theory.
Popularity of the ride is a variable you can't account with statistics yet. You can only predict. I predict it will be popular, especially for the next few months, which means expect long lines.