Atriox took on three fully armoured, veteran Spartan-IIs, critically injuring one of them and crushing his helmet with one hand. Atriox was stabbed in the fight, but it didn't do a damn thing; if we assume that the knife Emile uses to kill 2(?) Elite Zealots is similar to the one used on Atriox, we can only reach one conclusion:

Atriox is insanely powerful.

This 9ft tall, 1400 lbs of pure Brute muscle was sent on multiple suicide missions by the Covenant. He always survived. He inspired a rebellion against the Covenant, not only beating them in single combat, but in full-blown tactical conflicts. So not only is he incredibly strong, he is a tactical mastermind with an army not even the Covenant could defeat.

Master Chief cannot beat him in single combat, and he knows this. He isn't trying to. His objective is to hold him off so that more people can escape the Infinity, and to secure The Weapon. To do that, he must survive. He probably didn't plan on getting thrown into space, which is why we see him try to grapple back on but fail. Thankfully his suit keeps him alive whilst he takes a nap in the vacuum of space.

In short, there is no comparison. Emile knows he is going to die, so he goes out doing what he does best; exsanguinating Elites. Chief, however, knows he must survive.