Really though, we just all need to accept that the Overwatch timeline is thoroughly fucked and not try and put any sorta logic to it. It’s comic book shit. Widowmaker shot and wounded Ana many years ago while looking identical to how she does in the present day I just realized.. all this mess of trying to pin down the dates and exact ages like.. it’s no use! Especially to not just try and go “your f/f pairing is problematic”
To further your point, according to Blizzard the first Overwatch disbanded 30 years from the present of the game, and in the present of the game McCree is ~37 years old. So he would be 7 when Overwatch disbanded.
McCree was actually born looking exactly like he does now. He came outta the womb lit cigar and BAMF buckle already on him