Nimzo-Indian 

I agree 100% that the article should be Nimzo-Indian Defence, with a redirect from Nimzo-Indian.
We have the same problem with the Bogo-Indian.
Since articles already exist at the redirects and they have had edits, we can't do the move ourselves.
Probably the best bet is to ask User:Sjakkalle to make the move, as he's an admin.
He's also a chess player, so he'll understand why the full names are better.
(I wrote Defence above instead of Defense since it looks like that article was originally created using British spelling.
The wikipedia practice is to conform to the spelling that was used to create the article.
If the article is about a clearly British subject, British spelling should be used, and the reverse if it's a U.S. subject.)