Yes, Leonard is the starting SF and Green is the backup SF.
This particular discussion, which you started, was about Green as a backup SF.
Since the numbers were against all SFs, that would includes starters and reserves. Since the number is excellent overall, it stands to reason that it's even better when he guards reserves.
I got the stats from 82games.com, which is a much better source for information on the qualities of NBA basketball players than "off the top of your head".

@ barnes as a better SF than Green.