Here's a significantly faster way to tell which folder is in use, and even which folder is emunand and which is sysnand if you use both. It can also determine which emunand is which if you have multiples for any reason. This assumes you arent using a9lh to autoboot emunand.
1. In each of the folders there is a folder called extdata, on a computer, rename all of these extdata folders (I used extdata_bak)
2. Put the card in your system and turn it on. It will recreate home menu data and any theme you had will be gone. If you use homemenuhax, that will be temporarily disabled and you will be in sysnand.
3. Turn off your system and check your card. One of the folders will now have a new extdata folder in addition to the old one you renamed in step 1. This folder is your sysnand, keep a note of which one it is
4. To find your emunand, delete the new extdata in the sysnand folder and then rename the old extdata folder back to extdata. This will reinstall homemenuhax if you were using it, and you can get into emunand again. boot your system and get into emunand this time.
5. As before, there will be no theme and the system will make a new extdata folder. Shut down and find which of the remaining folders has the new extdata. That is your emunand folder.
6. Again, delete the new extdata folder and rename the old one back to extdata. This will restore everything to the way it was before. If this is the only emunand you use, you can now delete the other folders. If you use a9lh to autoboot emunand, you can also safely delete the sysnand folder if you want.
7. If you have multiple emunands, repeat steps 4 and 5 to determine which folders are which emunands.
You can delete what you don't want to keep. If for some reason you don't have a method to boot into some of the nands, that folder will never change and can probably be deleted.