This merge should be done. I tried, but I have repeatedly gotten the message The merge of Arvid Mattsson (Mattsson-33) and Arvid Mattsson (Mattsson-16) is already in progress by another user. If it is not completed in five minutes, you can complete it. Maybe someone else has been working on it, but I suspect it's gotten "hung up."
Also, http://www.wikitree.com/wiki/Matsson-27 needs to be merged to Mattsson-30, but I get the same error message when I try to merge or match those profiles.