I'm not a fan of that line of thinking. By that logic George Mikan would be an average big man compared to current NBA centers. Greatness, in my opinion, should be measured by what you managed to accomplish in your era.
I agree. However, in this case.
-Ken Shamrock was not the greatest of his era, either in terms of skills or results.
-Consideration should be made for how incredibly primitive, and how few serious fighters there were in MMA back then when comparing that very early era to later ones.
I love old-school NHB, but we have to be honest about what we're watching. The greatest fighter of that era, Dan Severn, was a washed-up amateur wrestler in his late 30's whose body was half-crippled from injuries during his heyday in the 80's, and who didn't learn or adopt to MMA much at all. (All this per Dan's own admissions, too) Look at what happened when Severn fought Coleman. (Coleman in my opinion being a greater legend than Ken Shamrock or Dan Severn)
Furthermore, there were guys back then who had considerable success and are even called "legends" who
started MMA with no almost fighting background at all. They were just big, strong dudes.
Think I'm exaggerating? Consider
-Kimo Leopoldo. A street fighter with no formal training who was big, strong, and on a ton of steroids.
-Polar Bear Paul Varelans, my username. Probably Tank Abbot's most impressive victory and a guy who made both Ultimate Ultimates. He was a huge, strong guy whose fighting background consisted of a little bit of high school wrestling.
-Gary Goodridge. A legendary arm-wrestler and insanely strong dude who had done some amateur boxing when he was in his early teens.
Again, even in this landscape, Ken Shamrock was good, but not the best. Even before Belfort, Couture, and Rizzo showed up, and Bas Rutten and Maurice Smith learned a decent amount of grappling, I would still rank
Mark Coleman
Royce Gracie
Don Frye
Dan Severn
unquestionably ahead of Ken. Of course, there are many others who were on a comparable or better level, especially in terms of skill. From the standpoint of pure skill, and not Ken's size and steroid advantage (remember, most promotions didn't have weight classes then), these guys were as good as or better than him;
Renzo Gracie
Mario Sperry
Igor Zinoviev
Oleg Taktarov
(I could include Ralph Gracie, Royler Gracie, and Rickson Gracie too, but they admittedly never fought serious competition.)
Where does that put Shamrock? The first King of Pancrase. A UFC Superfight champion. Someone who holds wins over Funaki, Rutten, Smith, Severn....guys who were all top level in their era.
Again, let's be honest about what we're watching here. Rutten and Smith had just started MMA while transitioning from kick boxing. Rutten admits his entire grappling arsenal back then was limited to trying to get a guillotine on the other guy.
And the second Rutten vs. Ken Shamrock fight was a work, as noted earlier. This was not Rutten or Smith anywhere near what they would later become.