Oh! Wait, you know how in TRACKS, Simmons tells Coulson that he looks MUCH too young to be her father? What if that's just a big cluehammer and that kid called Phil from the 50's playing with the Captain America shield in the film IS Coulson, and he's older than we think? Older than he thinks? What if he's a SHIELD super soldier experiment gone AWOL? He loves old shit, dudes, think about it.