I have 3 of the 4 from the set, and Philip is larger than Aladdin or the Prince. This series is actually not that had to tell authentic, IF you have some current authentic HM pins to compare them to. Or authentic old cast lanyards. The gold they used for WDW Cast Lanyard #1, #2, DL Cast Lanyard 1, 2, and 2.5 is a different shade. It is much brighter and more yellowish, if that makes sense. It makes the current HM pins look more silvery by comparison. So in good light, you can flip them upside down to compare.
It's always hard to tell from photos, but it almost looks like the Prince is slightly less gold than the other two. So he would be the one I'd be most concerned with, but it could just be lighting. I'll take a pictures of my backs, so you can see the size and placement of the boxes. But we are having a thunderstorm so I can't get good light.
So like your pic, Aladdin is on the left, Philip in the Middle, Prince on the right