Eastern is standing in front of Fleck, and Morris is standing behind him - yet Morris is closer to the camera? LOL - ok, bro.
You've fallen off your rocker.
Look where the their heels of their feet are in relation to the wall. The camera appears more centered in front of Eastern however, but Eastern if closer to the back wall than Fleck or Morris.
Morris's and Eastern's eyes matchup, so assuming their foreheads are similar, their height would be similar.
The only frame of reference is the wide part of the oar. Not sure how wide that is at it's wide point, but I'd guess 5 - 6 inches.
Eastern and Morris appear to be 1.5 oar widths taller than Fleck. That would be 7.5-9 inches.
Assume 7.5.
If Fleck is 5'9" instead of 5'10.
Add 7.5" and that would be about 6'3 1/2"
That's assuming oar width of 5", not 6" and Fleck's height of 5'9" not 5'10".