One could make the comparison of quality (not necessarily same skill set) the competition being relatively in the same ball park. Holloway=Bonnar: well rounded, hard to finish, both went full 3 and both were fully and completely dominated. Poirier=Bader: both had hot streaks going in, were considered top tier competition that was supposed to give a stiff test. Vera=Brandao: both muay thai specialists, bjj black belts and were top touted prospects during their UFC early days. Also, both beat top rated competition. Siver=Matyushenko: Both from the USSR, both very tough journeymen/almost gate keepers an although both lost prior to their respective fights with Jones/Conor, both were never so dominated in the fashion that they were in there fights with Jones/Conor.
One undeniable quality with Jones and CMcG is that we never saw either in trouble/and or tested before their title shots. At the time, people were making ridiculous assumptions about JBJ's potential and still till this day, we have really not seen him pushed to maximum capacity (maybe Gus fight but that is for a different convo). I'm not saying McG will never be tested, as I am sure he will, but I am saying that people are making the same outlandish assumptions about his TDD, his striking defense, fight IQ, etc....one cannot make logical and definitive assumptions on weaknss when said fighter has been completely and utterly dominant.
This is why I am soooooo excited for Conor/Aldo. In many ways it is like Jones/Cormier but we are talking about a strikers delight vs a grapplers delight. Anything is possible in a fight and for sure, for the first time, we will see one of these 2 look mortal: which one? If anyone says they definitely know, they are speaking out of their asshole.
EDIT: Oh, and agree, Aldo is markedly better than Shogun but if you look at the time, especially after the Pride merger, Shogun was considered #2 P4P fighter in the world. Shogun has completely fallen from grace but there was a time that he was not only considered the greatest LHW to ever fight but the scariest striker to possibly ever compete in MMA. Now, revisionists history rules the day, but for sure Shogun was an absolute killer and no one, absolutely no one, ever walked thru him in the fashion JBJ walked thru him and it was considered impossible that anyone would/could dispose of him in the way JBJ disposed of him.