It wasn't a video per se but the data or KPH they were able to determine for Arjen Robben speed came from Data collected by examining video footage of him. So the point remains the example you provided to measure the speed of soccer/futball players came from clips of soccer players dribbling down field.
So on one hand, you're telling me dunking/dribbling isn't a good way to measure athletic ability as you did in this post.
On the other hand, the examples of speed you are providing of Soccer/futball players dribbling downfield as you did in this post
But with that said, our definition of athletes is conflicted with yours. That is why there is a misunderstanding when you say dunking isn't a good measure for athlete's vertical. Because here, most athletes play multiple sports growing up, it is a matter of choosing one for a profession. Guys in the NFL/NBA more like played both sports growing up as well as multiple sports such as wrestling, track and field, baseball etc. That's what athletes here do. So when we say "Athlete" we say it in terms of that person can excel in almost any sport they dedicate themselves to.
So when you say an athlete from another sport would be a fish out of water dunking, that doesn't compute with us. The majority of the guys in the NFL can dunk because the majority of athletes here compete in multiple sports growing up. Even the fat boys you guys like to make front of so much and short 5'8 manlet slot wide receivers like Cole Beasley.
Jon Jones is considered the runt of the family because that is what he is. He was the least athletic of his brothers and the least recruited as an athlete. The whole point about Jon's inability to dunk has nothing to do with dunking and everything to do with gauging his vertical which is a measure of his explosive power output. The kind of output that allows wrestlers like GSP to have such an explosive double. If holding the ball is still an issue for you, Jon jumped an attempted to touch the rim without the ball before attempted to dunk. It is clear that he doesn't have much of a vertical and not very explosive. But Jon was wearing jeans and was casually hanging out not in competitive mode so I will cut him some slack and say we still haven't seen his max vert. His younger brother however could dunk in high school. He played multiple sports. Chandler's combine results showed he has a 35 inch vertical, very explosive for a man with his height and weight. 6'5 265 pounds and a 35 inch vert.
So Chandler Jones is taller than Jon, weighs more than Jon, stronger than Jon, has a better reach than Jon, he is more explosive, and he has shown an ability to excel in multiple sports. So here, Chandler is considered more athletic. In terms of MMA, what Jon has over chandler is skill and technique. Both of which can be taught. After the skill gap closes, other attributes come into play. Like athleticism, something which cannot be taught.
As for Arthur Jones, he was an undefeated wrestler in high school unlike Jon. He was a better wrestler growing up Arthur is a two-time New York state HS champion in wrestling. He chose football over wrestling, which is often the case here. Here are some very outdated lists of NFL athletes with wrestling backgrounds.
http://www.sectiononewrestling.com/documents/nfl_players_wrestled.html
https://uselitecombat.com/hey-coach-arent-football-players-wrestling-nfl-players-wrestled/
As you can see, there are a bunch of wrestling champions in the NFL. As I said, I can't speak for other countries, but the athletes here go where the money is. All these wrestling champions chose the NFL.
I know everyone likes to make front of Arthur's weight but just remember that Gut Fedor is the HW Goat of MMA. Gut DC is the former HW champion. Tim Sylvia is one of the most successful HW champions in UFC history. Miocic is the current UFC champion and he comes from Baseball. So history has shown us a fat guys can become a champion in the UFC and so can a ball sport athlete like Miocic. As for conditioning, Brock Lesnar who doesn't have the best conditioning and he was Champion. Ironically, all these muscle bound guys are who we see gassing most often, not the fat boys. You can have a gut and still be well conditioned and very athletic for you size. & If you are a dominant wrestler, you can control the fight even against better conditioned fighters. Kind of like how Nick Diaz has triathlete level conditioning but many of the WW wrestlers could still hold him down for 5 rounds.
Now with all that said, saying Jon's brothers are more athletic than him doesn't mean Jon isn't athletic in his own right. He is still one of the more athletic guys in MMA. Jon is an anomaly for the sport, you don't see guys with that kind of frame (Height/reach) with such dominant wrestling, in that regard, he is very athletic. Usually the taller guys lack wrestling and are weaker in terms of Grappling and that is how they are exploited. That is how Fedor beat Semmy closed the distance and exploited the Semmy's grappling weakness. In Jon's case, he is arguably the strongest wrestler and the better grappler as well. That gives him a huge advantage, in the standup he has the range advantage and pick you apart from the outside. So you have to close the distance to even damage him. When you do get in close on him, you are in grappling territory where Jon is also better as wrestling is his biggest strength. He is very durable as shown from the 1st Gus fight and the shots he took from DC. From a strategic standpoint, that is why Jon is so hard to beat.