I came up with it for an idea to make the Fighter into a Captain. That is, a person whose greatness and prowess is an inspiration to allies, and a source of dread to enemies.
The idea was, you mostly take the Battle Master fighter, and you put this feature on it in place of the normal extra attack progression, and suddenly the tactical applications increase, Rally becomes a bigger effect, etc.
Then it should just be a matter of adding some minor follower and stronghold features that mostly effect downtime, and let the fighter use Action Surge and Second Wind for allies (perhaps with a feat), and you’ve got a Captain.