I managed to fix it. I tried all fixes simlutaneously, so I’m not sure which one specifically solved my issue. I:
1. Ensured full privileges to the roms and images folders
2. Deleted all pre-exisiting images (both in rom folders and .emulationstation
3. Deleted all gameslist.xml files from the roms folders, and replaced all gameslist.xml files from within .emulationstation folder with empty gameslist.xml
4. Re-run the scraper
5. Success

Thanks for the help guys. I suspects having tried the native ES scraper first is what messed everything up.