In Nashville on Sunday, the Philadelphia Eagles survived a game they were never supposed to struggle through, as Jalen Hurts delivered a 3-yard touchdown pass to Darius Cooper with nine seconds remaining to edge the Tennessee Titans 24-20. The victory preserved an unblemished 2-0 record, but the manner of it — turnovers, a hobbled star, and a late deficit against one of football's weaker teams — raised the older, quieter question that follows every team that wins without convincing: how long can fortune substitute for execution?