Originally Posted by metaphysician
Unless they had any number of superscience tricks available to avoid having to do any of that. Cloned "blanks" are hardly unknown in science fiction, and neither is fast growing clones.
Yes, but Gregg and Whedon have teased that the secret of Coulson's resurrection is a dark one. Coulson being the inhabitant of the body of a sentient human being who was essentially killed to make way for him is pretty dark. Phil Coulson is being portrayed as a decent, compassionate person who values human life. He would probably be extremely upset to find something like that out.
Another possibility I've thought of is that the Phil Coulson now working for SHIELD isn't the Phil Coulson of the MCU's universe at all, but a version of him from an adjacent universe who was brought over with some alien technology. In this scenario, Fury's scientists could have been attempting to use what they thought was time travel technology to reach back to a point prior to Coulson's death and pull him forward. Unfortunately, that's not really possible as it would cause all manner of paradoxical problems. So what the process actually did was reach over into a universe adjacent to our own, where there was also a Phil Coulson still alive, and pulled that man into the MCU universe. The scientists quickly realized the mistake that they had made, but couldn't sent Phil2 back. When Phil2 figured out that something drastic had happened, he told them that he was living an entirely different life from Phil1: wife, kids, a job as a high school principle, etc. So Fury & co. wiped Phil2's memories of his real life and implanted false ones from the Phil Coulson they knew.
Imagine if that were the case and Phil found out that he'd been snatched from his life and loved ones and could never return. Cue all the angst and tragedy. Of course it's not to be, but I'd love to see something as twisted as that.