It is and it all has to do with Lean Body Mass, and max lean body mass range. Humans are not 'designed' or evolutionary meant to have tons and tons of muscle mass or tons and tons of fat. This below chart is a pretty good universal indicator (for males) based on 6% body fat and what a 'natural' lifter could accomplish. MMA isn't bodybuilding but Lean Body Mass, and 'muscle mass' is the same everywhere. Muscle mass, and strength is important in MMA and increasingly so. It is why camps have overtime become more grappling/clinch heavy and that often factors in with strength. It is why guys like Rockhold, Jacare, Weidman, Romero etc are so jacked.
That is why below Middleweight (MW) you stop seeing +6'0 fighters. And once you go below WW you basically never see them unless it is a skinny fat guy in a low level organization or a skinny fat like Carlos Condit @Welterweight who does get manhandled quite frequently. Then you have some guys like 6'0 Cerrone who fought at LW and did okay cause he was pretty lean but not the strongest or strong by any means. Cerrone is now better at WW though with a bit more mass. But it worked for Cerrone most of the time since his style was kickboxing and distance striking not clinch or grappling and he managed to evade a lot of that via good footwork.
In any case the science does not lie and neither do the experts of MMA camps and strength and conditioning coaches and nutritionists and guys like Dolce.
https://www.builtlean.com/2011/03/30/how-much-muscle-can-you-gain-naturally/
@^^6% body fat. Pretty good chart. Brock was clearly above 6% but even at say 15% he was high above a possible normal threshold. I am pro a lot of GNC stuff being used. I think a lot of PED's should be legalized/allowed. I think an acceptable range of testosterone should be allowed and you can't go above that. However, the facts are facts.
FLW, BW, FW, LW, WW tend to be the most jacked/shredded, and conditioned from what I have seen. In any case most WW tend to be in the 5'9-5'11.5' range and be on the max threshold of 'optimal' lean body mass. Most LW tend to be 5'8-5'10.5 and be pretty ripped. Most FW tend to be 5'7- 5'10 with a leaner frame less muscle mass than LW and smaller frames. Or you get some FW like Conor who is really a natural LW (more or less). Then you got BW who are on average what 5'5.5 to 5'7 maybe a max of 5'8? Then FLW who are almost always sub 5'6 and smallest bone size/frame of anyone.
I'd say the difference between FLW and BW is in muscle mass, height and frame size. The difference between FW and BW though seems to be mostly on bone size/frame size. And the difference between LW and WW is a muscle mass difference or in some cases natural frame size.
MW and LHW by comparison seem to be pretty even with LHW being more 'fat' and carrying excess weight. And most LHW's could comfortably fight at 230-240lbs as HW's.
