I like the flights of fancy this sort of story induces. You know what they say about chaos theory, butterfly flapping its wings in Australia causes a tornado in Canada etc. The 80's era needed a specific chain of events leading up to it, so any changes for the better in the 70's (Revie or Robson instead of Bingham) would likely mean the 80's era not happening.
Obviously, that tweak might also have led to twenty years of sustained dominance and the ability to truly take advantage of the riches of the Premier League when it turned up, unconstrained by the disastrous management of late-era Philip Carter, Dr David Marsh, Peter Johnson, Bill Kenwright etc, and we might now be sitting on 20 titles!
But if you hold a gun to my head and tell me to get into the time machine to ensure Bobby Robson or Don Revie take over in 1973, I ain't getting in.