We've been around long enough to understand good timing.
There is no version of Conor that ever walked the earth that was the best lightweight. He got the shit beaten out of him by Nate Diaz FFS. But he could beat Eddie Alvarez, who himself got his title shot on back to back controversial decisions, on one night.
There is no version of Jiri that beats DC, Jones or a prime Gus. I doubt he could beat prime Rumble. But because of a confluence of events, Glover held UFC gold for a single fight in his 40's, shortly before retirement. Jiri could have a WAR with him and get a win.
It is what it is.