The names will need to rematch, but only the portions outside of brackets and parenthesis so if what ever is inside ( ) is wildly different you can ignore it. As long as the game name matches the media, you'll be good. Delete the games and do an import, but uncheck all of the boxes to download anything and the process will go fairly fast. You can then see if any of your games are missing media. Click a game in your system of choice, then Ctrl + A to highlight them all. Then go to Tools -> Download Metadata and Images. It will bring up the wizard and ask you a question with 3 choices. Pick the bottom choice and it will only download media for games that are missing their images. You can then use the tool to clean up images for the images that are no longer associated to anything. That clean up could take a while though if you have a lot of media. If you want to see if any of your games need new images then you'll need to select the top option in the Wizard for re-downloading metadata, but of course this will take a lot longer.