Stealing a possession only applies if you stop them on their initial possession. Turnovers also steal possessions from the opponent. But on average, teams are gonna get a dozen possessions in a game so I don’t put much stock in the idea of deferring to steal a possession.
But in deferring, if you can score at the end of the first half and on the initial drive in the second half, it can be a huge factor in swinging the game. The “double dip” is a real advantage when it works out that way.