Really? I'm annoyed that iPhoto for iOS is sorting all my synced pictures in chronological order. They don't appear in the custom order I've put them in iPhoto or Aperture. I don't want them in random order, but most of my iPhoto/Aperture albums on my Mac are in a particular order so they tell a story. While I do my best to to keep them approximately in chronological order, sometimes a later one just looks beter coming before an earlier one. There's no way to change the order once the pictures are in iPhoto for iOS.
I just sent Apple feedback asking to be able to manuall change the order of pictures in an album in iPhoto for iOS or for it to al least mirror the order they appear on my Mac's photo application.
Actually the sorting in Iphoto for IOS seems to be completely random and is neither chronological nor a custom order that I have used in Aperture. Basically there seems to be no connection between the sort sequence of the MAC application and IOS application. This is frustrating if you have over 400 pics in an album as I do.
As you suggested they should at least mirror the order in which they appear on the MAC photo application. This seems to be the case for the generic IOS photo app which is delivered with the IPAD.
I've seen this too. In the Photo app the photos appear in the order I had them before I synced them to the iPad. But in iPhoto for iOS the order is different. Other users have mentioned or complained of this also. All I can suggest is that you leave feedback to Apple here