Fedor would not be a middleweight. Also, Jon Jones is really tall, and is also abominably large for a LHW. Jon Jones would look bigger than many heavyweights.
Furthermore, Tim Sylvia is not exactly all muscle - and he is not the "Jon Jones" of his weight class. He was never the best HW, 2nd best, or even 3rd. Randy Courture even beat Tim Sylvia (who is smaller than Fedor). In fact, Dan Henderson has fought several heavyweights, and he is (much) smaller than Fedor, and he has an incredibly hard time making middleweight. Fedor was clearly bigger than Matt Linland, who was a middleweight. Fedor isn't very tall, but he's not exactly narrow framed.
The two best heavyweights of that time that Fedor also fought were Nogueria and Crocop - not exactly giants. Fedor was not dramatically undersized for his time. Coleman and Randleman, who were more from the previous era weren't giants either (muscled up and roided, but not large).
Jones is stronger than Fedor? Perhaps, but isn't Fedor stronger than Nogueria?
You also did not show a comparison of Usman to Jones.
Showing pictures of guys next to tall guys doesn't mean that much. Why not show a picture of Fedor next to Nemkov? Or even more directly applicable, Daniel Cormier? He's not a middleweight, no chance my guy.
Fedor was on the small side, but saying he would be a middle weight today doesn't seem accurate, and is not relevant since his prime isn't today. He wasn't the Sakuraba of the hw division, he was the Mike Tyson (except much better).
Heavyweights might be bigger now, but Fedor's prime didn't happen in this era, so I don't see why that would matter.
Fedor's natural weight class doesn't exist yet in mainstream MMA.
EDIT: I reread what you said. You said middle weight at best. At Best? You're inferring he would be a welterweight???
