You're ignoring the diamonds you'll be making from 12 hour filming. Those diamonds earned can be invested into shortening the 12 hour filming.
Last event I did a constant 2 hour and 6 hour for sleeping. tt1000 dd 12 hour and we both ended up with enough pumpkins for 3 outfits but tt1000 ended up with 40+ diamonds extra. Those extra diamonds can be used for a 4th outfit or something else.
Your luck has to be pretty good to get more than 3 outfits.