I’ve made this point before, Cro Cop had a decent amateur career, won a couple national titles and even won silver in the world military games. That experience clearly rounded out his game, and made him a kickboxing champion and a top K-1 contender, and eventual Pride champion, but his boxing probably wouldn’t have translated well into the pro ranks. He had good power and hand speed, was very physically strong but was very difficult to manage (why he ended up not fighting in the 2002 k-1 gp, which he was the favorite to win) and had a glass jaw which led to several ko defeats. You can get away with having several losses in kickboxing ( to a smaller extent in mma) and still get big opportunities. A couple bad losses in boxing can end any chances of making a brake though in your career. Simply said a boxing title was never going to be in the cards for old Cro Cop.