i'll put it to you this way.
I am a huge boxing guy.
I love Roy Jones Jr. But would I put Roy Jones Jr on an all time great p4p list on resume over say...Lennox Lewis?
Well Roy dominated a pretty mediocre (at the time) Middleweight, Super Middle and Light Heavyweight division in the 90's/Early 00's (with the exception of course of James Toney, a young Bernard Hopkins and Montell Griffin was not too bad either).
Whereas Lennox dominated a talent rich heavyweight division of the 90's with Evander, Ruddock, Mercer, Morrison etc.
So in these sorta lists, while it might be unfair to a Roy Jones it is the reality of it all
Those are fair and understandable arguments.
I have DJ so far up (basically at #1 alongside GSP) because while his division wasn't the biggest shark tank ever, his opponents were (as mentioned) still very good fighters and two of his losses came against fellow all time greats in Cruz and Cejudo (with the Cejudo fight being highly controversial).
His well-roundedness and ability to blend it all together is unmatched by everyone not named GSP and DJ might just be a better striker too, who knows.
So DJ stands at 30-3 now, was insanely dominant for a very long time (and still is, i guess), has not even the slightest asterisk next to any of his accomplishments and - as mentioned - almost exclusively lost to other greats of the sport - always by decision too.
GSP is also insanely well-rounded, fought in a shark tank of a division, was slightly less dominant than DJ, but still super dominant and managed to beat everyone he stepped in the cage against, with one of only two losses coming against the prime version of second most accomplished welterweight ever in Matt Hughes and GSP was very young too, back then - the fact that he finished Hughes twice is the icing on the cake in that regard.
Khabib's career - albeit i wish it could've lasted longer - was as close to flawless as it gets.
He fought in the most stacked divison of all time and displayed a level of dominance that was unheard of - he rarely had more than a scratch on him after his wins too, which is why i rank him extremely high.
I guess you can figure out somewhat why i ranked the other guys the way i did - i'm just too lazy to write much more right now, haha.
Take care!