When it comes to elite level MMA, the smaller guy will face a big disadvantage majority of the time.
It can be nullified by fighter styles like if the smaller guy is a much better grappler.
When it comes to striking the smaller guy will have to be much better just to overcome the height and reach. This isnt always the case and some MMA fights will disprove this!! If you give them the same striking skills then the taller fighter should win 8/10 striking matchups.
Search for Genki Sudo vs Butterbean on Youtube/Google.
For striking look for K1 Koaklai vs Mighty Mo.
Franklin,Gouveia,Maia,Kharitonov,Hunt,Liddell,Pari syan,Hardy,Shlemenko,Machida,Gomi,Bustamante,Evans ,Edgar,Hathaway,Bonnar,Murray,S.Carter,Ludwig,Pett is,K.Gill,Sobral,Mousasi,D.Cruz,Arona,Nogueiras,Co te,Ole Laursen,Kawajiri,Sakuraba & K1 Lebanner!