Do both bike frames have the same seat tube angle?

If so, then your math is good. (if not, then you need to recalculate)

Consider toe overlap. If the smaller one will have your toe hitting the front tire during low-speed parking lot maneuvers (which I find really annoying) then I would go larger. If it's the same either way, I would choose the smaller frame only because it's going to be an ounce or two lighter.

The smaller frame will require more spacers under the stem (or an upturned stem) to get the stack height correct. And that may change the total reach of the bike just a bit (which may mean a recalculation of stem length if you are picky....or you can just get bars with more reach).