The ordering in the Photos app on the iPad is out of your control. It sorts by either creation or modification date. I don't remember which. Depending on what view you are using it sorts in ascending or descending order. Again, out of your control.
I suppose you could try editing the date in iPhotos on the computer, but I'm not sure what affect this will have. Besides never having tried, I'm running a version or so behind on my iMac.
People who want better control of how their photo albums are displayed and sorted generally use a thrid party app like Photo Manager Pro. There are lots of them, many with specialized features.
You can't get completely away from Photos. You need it for the camera, and for photos you need to share between apps; but for your permanent photo collection a third party app is a good choice.
On the other hand, I only keep a couple hundred photos on my iPad (mostly of family and friends), so Photos is enough for me.
