Will my folders work better if I use a microSD card?

It depends on the tag values. If all tag fields are blank, my experience is the player will dump everything in the ‘unknown’ folder and play them in their file structure order*. You need to look at the tagged value for those Bob Marley files. If the album fields are identical (which I suspect), then the clip just uses that album name. The play order within an album is determined by the tagged track#. The displayed title will be the title field in the tag, else I believe the windows name. That’s why with all these variables it’s so important to tag everything.

* file structure order is the order files are stored within a directory. This has nothing to do with what windows displays, but is the order in which the files are written to an empty directory. It’s what you will see if you list the files from command (dos) window using the dir command without switches.