You're right. I just picked a set of mp4 files and didn't look at them.
They are from a LaunchBox scraped set and have different file names.
I found the matching name set and it works just fine.

Thank you.

@greenhawk84

Click on the thread below. It should solve your problem.

RetroPie - Convert Non-Functional videos to functional videos - Easy free batch method on Windows - also size reducer

@chubsta Anytime. Something else that may be useful to you is adjusting the crf value, sometimes called constant quality. A setting of 22 is usually default but that will make large videos that look good full screen, if its just going to be in the corner of your theme you may want to go with a higher value. I use crf 28 (the higher the value the lower the quality) This brought ~100gb worth of videos down to just over 32gb

@mitu Tested, confirmed working with Universal XML scraper

You could also just add them to the gamelist entries for each game?

Scraper doesn't like some formats. I had a gamegear set in 7zip and it wouldn't scrap other then one zip file I had there. Lucky I had that game otherwise I wouldn't noticed it.