http://www.mobygames.com/game/dos/shadow-knights

it's obviously the same game from Softdisk... just licensed to Froggman 3 years later and given a new title (and title screen).

I disagree with the merging. There's many Froggman alternates of softdisk games with different packaging, like Dognapped (Rescue Rover)

Yes, and that one is a good example - it's entered as a single game with an alternate title (so both show up in search results). Much more intuitive than having separate entries, and all the extra release information and packaging scans can still be added.