This is a very small issue. The order doesn't really matter that much. Actually, a 2 tuple will always sort before a 3 tuple anyway when using sext. I'm just thinking that down the line we might want more markers and people will get creative with the names. So maybe adding the concept of keys that are global meta-data for the partition might make that less likely.  That way we could avoid eve more special code by having some to_md_key function and such.