When does a top 3 team have a signature win ? They are most often either favored or a pick'em, with no guaranteed losses. By your definition, Saban didn't have too many sig wins either.
Sabans sigs are the rings on his fingers. Now you’re being daft
Over the past decade, Alabama's most prominent and memorable wins in football include their five national championships (2009, 2011, 2012, 2015, 2017), six SEC Championship victories (2009, 2010, 2012, 2015, 2017, 2020), and a streak of 15 consecutive seasons with a top-10 ranking.