Redirects only need categories if, and only if, the title you are using for the redirect was an officially used title. In other words, lets say you're talking about "Mega Man X2". If you are making a redirect for "Rockman X2", you DO need categories because the game was officially released in Japan under that title. However, if you're making a redirect for "mega man x2" or "MMX2", you do NOT need categories because you're just making short cuts to the real article. But Rockman X2 should appear in the Super Nintendo and Capcom categories because there really was a Rockman X2 on the market. We just don't need a whole separate guide for it.