Whoa whoa whoa.....first of all Brock was hotshotted to the title....he went
1-1 to earn a title shot against culture....literally the whole top ten could do the same
Secondly he didn't "fail miserably" in the nfl....he wanted to play defensive and they wanted him as a guard so he quit(mind you he did this without ever playing college ball and very little in high school)
Physically he was more of a specimen than any of the NFL players........4.6 second 40 yard dash, 35 inch vertical(bigger than Kevin durants) and 32 reps of 225 pound bench press all while weighing nearly 290 pounds
What he was lacking was polished skill from years of playing football....it had absolutely zero to do with athleticism