It's very possible that a highly skilled HW boxer like Anthony Joshua or Tyson Fury could catch Stipe on the feet, and then knock him out. I'm reminded of that time Tim Sylvia -- fresh off a loss to Fedor Emelianenko but still a highly regarded heavyweight -- was quickly knocked out by Ray Mercer.
The top HW boxers are slightly more athletically talented than top HW MMA guys. They have better cardio, better toughness, better speed, etc.