@alphabetapie most of the dat files for the supported MAME emulators in retropie are available in the docs: https://retropie.org.uk/docs/MAME/
so from there you can see how many versions of a given game there are. on latest mame i can see 2 versions of vcop and vcopa (revision A). these don't seem to be language designations.
doing some research: http://adb.arcadeitalia.net/dettaglio_mame.php?game_name=vcop
0.155: Changed 'Virtua Cop (Revision A)' from a parent set to clone.
so it might be that rev a was the japanese version and from 0.155 the parent is USA language, or it could be a system menu thing. but without logs or any kind of diagnostic info we're just guessing.