Dutch would most likely win. After, those biceps are huge. It takes more skill to fight in a jungle than it does to in a corridor. Also, Dutch managed to make his own weapons near the end of Predator.
However, everything that Hicks had was standard issue. However, his backup shotgun may have been a personal weapon, but I doubt it. Yes, his armour was pianted a bit, and he most likely had a non-standard issue boot knife.
Hicks would have the slight advantage of knowing how to use a pulse rifle, what sort of temerature it can take, how resiliant it is, and how reliable it is. But Dutch, being part of a spec ops unit, would eventually figure out how to use the pulse rifle.
But I'm going to assume that they both know how to use thier guns.
A Pistol. Any soldier knows how to c0ck a pistol, and almost every pistol would have the same firing sequence. After all, all you have to do is insert the magazine, pull the slide back, and pull the trigger.
The Knife. It would depend on what sort of pocket knife they were using. a switch-blade, a throwing knife, a bowie knife, a combat knife, or a normal knife. They would each have the skill to wield a knife in a deadly manor, however, Dutch has more muscle (Did I use the correct spelling here? or did I say the clam like thing?) power, and that would give him an advantage in the fight.
And the fist. We all know what would happen in this case.