When I was in another sport (Track cycling) this type of debate came up.. Pro football player vs. Track cyclist.. one decathlete (Jr college type) started on the track and you could see some hints of power to the pedals. 4 years later he is really fast. But world wide not so much. He has the dedication for cycling that he put into T&F events. Another high end football player took his hand at cycling but not so much.
Some pro foot ball players went into Grid but did not make an impact. I spoke with a ex high level football pro and he is starting out CF. He might come and train but he is injured right now.
I could see a 10 event person coming into crossfit and doing well. It would take a while but they could do it.
I played sports (cycling, power lifting, running, Marines, Sailing, cycling and now Crossfit) Crossfit involves many other aspects, mental, recovery, diet.. I get my butt kicked regularly by some other guys my age. So many things that you have to train.. so many injuries..
All time bests- Bench 450#, Ran 3 miles off road in 18 min, 4.7ish 40..I just say this because I used to be strong. Now middle of the pack. 1 rep max type of events are usually 1 out of 8-15 overall. BB cycling is used more often.
If they program Decathlon type of events the person will smoke them.
CrossFit likes to find people and do stories on them when they come from a high level past sport. I was one of them..