It really doesn't have anything to do with how the files are synced but how the playback device reads the files on the disk.
It depends on a few factors really. How are the tracks named, are the tags filled in correctly and what are you using to read the flash drive and play back the tracks.
Most players will either order the files based on the track number tag or based on the filename in which case you should have the track number at the beginning of the filename.
So, in the case of 'The Endless River' I have the files named as follows:
01 - Things Left Unsaid.mp3
02 - It's What We Do.mp3
03 - Ebb and Flow.mp3
04 - Sum.mp3
...
...
etc, etc
Because the media player in my car will read the files in filename order.
Some older players, specifically earlier car audio systems would ignore all this and just read the files in the order that they were saved to the flash drive. This is more a failure in the playback system than in how the files are saved to the flash drive. There are some utilities available that will sort the file order to overcome these limitations.
If this is your problem then have a look at this thread on the HydrogenAudio forums
http://www.hydrogenaud.io/forums/index.php?showtopic=79667 which explains this and offers some solutions.
I hope this helps.