It's pretty objective. Big changes in favour of distance, circling and wrestling / clinching, all against Cro Cop's style and strenghts.
Opponents did not have to try to guess any more in split second is high kick coming, or middle kick or left straight, they simply could step back on distance, defend by movement, run to the side, or by constant circling evade situation in which they can be hit, and in which his kicks can be set. They could use weight leaning on the wire fence for long time to tire him.
Cro Cop naturally had problems to reach guys with longer reach who moved around like Schaub, Mir, Kongo, JDS, and was not able to get them in situations in which his kicks can be set, and that is all very different in the ring with lot less space, 4 corners, square shape, cutting of angles and movement and same environment and movement rules and habbits as K-1.
For other fighters who are grapplers or do not rely on kicks and seting up kicks changes were less important and less visible, so comparasion to Nogueira & Co. is not that relevant.