That's really funny you should ask this, because my DH is totally confounded by my uncanny ability to automatically remember what soaker goes with what diaper. It is kind of weird. I'm like some kind of diapering idiot savant.
If they are all mixed up right now and you are confused about what goes with what, the only advice I have for you is to sit down some night and see what soaker/diaper combos work best, and mark them like you were talking about so in the future they will all match up easily. You may not end up with the original set, but at least they will fit, KWIM? Or, you could go back to the website you ordered each one from and see what the soaker looks like and match them that way. Sorry, not much help.

If they are all mixed up right now and you are confused about what goes with what, the only advice I have for you is to sit down some night and see what soaker/diaper combos work best, and mark them like you were talking about so in the future they will all match up easily. You may not end up with the original set, but at least they will fit, KWIM? Or, you could go back to the website you ordered each one from and see what the soaker looks like and match them that way. Sorry, not much help.