Code Compare has a lot of difficulties to deal with scope changes. More than often, adding a namespace will mess up the comparison algorithm pretty badly. You'll end up with a billion changes in a file because all the lines have been changed (added tabulation) and one line have been added at the top. I've even seen it glitch and report that all the lines were new content...

A nice solution would be scope detection. Limit the comparison within scopes. Detect scope changes etc. That way, adding a namespace or a try/catch block could be detected and merged as one change.

This is valid for any language with scope, including xml and json.