Sega/Mega CD headers have incorrect serials

As discussed in this reddit thread: https://www.reddit.com/r/RetroArch/comments/17860mt/comment/k52yvgo/?context=3

It appears Sega CD games semi-frequently have the wrong serial number in their headers, leading to incorrect matching when we scan them. Some examples:

Tomcat Alley (USA) - Appears as Wonder Dog (Europe)
Sol-Feace (USA) - Appears as Wolfchild (Europe)
Silpheed (USA) - Appears as Double Switch (USA)
Prize Fighter (USA) (Disc 1) - Appears as Prize Fighter (Europe) (Disc 1)

In each of these cases, the actual game's header includes the serial of the "appears as" game, and the "appears as" game also has that same serial in its header. This unfortunately indicates that checking headers is unreliable, at least for these games.

Would it be possible to have a list of games where we "if X serial, do a manual checksum to verify"?

I believe this issue started following this still-excellent and much-appreciated PR: https://github.com/libretro/RetroArch/pull/11719

If that's indeed the case, would it make sense to revert Sega/Mega CD back to the old method?

Start by reviewing PR 11719 and the linked Reddit discussion, then compare the Sega CD headers and serials for Tomcat Alley, Sol-Feace, Silpheed, and Prize Fighter. Done means the affected games no longer match the wrong entries, with the chosen handling documented or covered by the repository's relevant data and matching checks.