I kept asking "Why?" and after enough asking it finally came to light that while the ask was centered around "comparing team X to team Y" it REALLY came down to FORECASTING, and "how do we know that we can deliver to the pre-determined timeline." Based upon that nugget I was able to table the team comparison exercise (under the auspices of "get them moving, keep them honest, set honest expectations, re-evaluate later") and concentrate on the whole estimation vs. forecasting vs. commitment discussion (@hdietrich this is where #NoEstimates comes in ).
I was able to convince TPTB to give me some time to get all the teams to reach the same standard of grooming that Vasco prescribes in the book (only 1 or 3 point stories, nothing more than two days, etc.) which will then lead us to become "predictable" and based upon that we can prognosticate on what we MAY deliver in the future.
As with everything else, I solved this problem and found the new problem of "we need to groom the backlog well enough to put everything at comparable size so we can forecast." Now THIS is a problem I'm very happy with!