I would agree with this as in essence, the Kazekage and Kage are 2 different treasures.
They both should operate on different reward tables.
It's prolly like drawing Ao in Sage, and seeing him again in Kage (although he's common then).

Well considering that Sage treasure was available much earlier and we still don't have a definite date on Kage treasure... it was a viable risk to take.
He's had at least a few mths of playtime and is still popular in my server... for that round 1 un-interruptible acupunture.