tom, just look at the fielding stats coming up through the minors. Desmond, until last year never had a year where he finished with under 30 errors.
I'm not a huge fan of errors as end all be all of measuring fielding, but its clear who has always been the technically sound fielder of the two.
You're not a fan of errors because you are correct in assessing that errors matter far less than range.
And Desmond has clearly made significant reductions in his error rate, so I am discounting his career error stats because that's an area where improvement is possible.