Overeem is probably the best striker in the HW division, and has so much more experience compared to Ngannou. Ngannou only has 5 UFC fights, and only has 11 fights, and really hasn't beat good competition. Overeem on the other hand has 59 fights, and has 12 UFC fights. He has beat Vitor 2x, Werdum 2x, Mark Hunt 2x, Brock Lesnar, Frank Mir, Stefan Struve, Roy Nelson, JDS, and Andrei Arlovski. Just watch, Overeem will show everyone just how good he is.