What made Kirby Smart one of the strongest branches on Nick Saban's coaching tree?

On3 image — ATHENS, GEORGIA - NOVEMBER 23: Head coach Kirby Smart of the Georgia Bulldogs shakes hands with head coach Jimbo Fisher of the Texas A&M Aggies after their 19-13 win at Sanford Stadium on November 23, 2019 in Athens, Georgia. (Photo by Kevin C. Cox/Getty Images)

Reddit user u/bullcityblue312 asked a question on the CFB subreddit about Kirby Smart and Nick Saban that caught my eye: "Why do you think Kirby Smart has been the most successful coach from the Saban tree?" Jimbo Fisher immediately came to mind as someone who might have something to say about that.