We don't need both. Actually I wanted to creata a tag synonym. Turns out I can't... Unless
Users with this privilege and a total answer score of 5 or more on the tag, can suggest tag synonyms. Users with a total answer score (total upvotes minus total downvotes) of 5 or more on the tag, can vote for tag synonyms.
But I guess we could go this far and just clear out pi0 and further retag question if it ever comes up again.