OK so here is the thing. In RL MC dosn't have his newb friendly aim assist and we all know without aim assist you can't hit shit in Halo. That's point 1. This leads into me second point which is the Doom runspeed is 4x the halo runspeed, you don't jump like a floating moron and are much much much faster. MC wouldn't be able to hit the Doom trooper cuz his runspeed is nerfed to make the game easy for people that suck at FPS.
Dooms rocket actually travel quickly.. and the DBS well.. shield or no shield that baby would cus MC down in a single shot. You have to remember when you play Halo you feel like you''re running in Quicksand.. when you play doom you are ****ing moving quick, can circle and strafe jump and are generally more bad ass. Thats just considering d2 weapons.. if we get into D3 and the black hole generating weapon, chaingun that shoots a thousand rounds a minute and rapid fire RL that has a 7 shot before reload capacity, available armoring and we're talking MC getting rapped by Doom guy and tea bagged infront of his mom.
I mean common, with 200 armor 150 HP a Splazer would take hit after hit to do anything. All the Doom trooper has to do is fire a black whole in the vacintity of MC and hes going to be eating lunch in another dimension.
Bare in mind this dosnt take into account any of the expansion pack weapons and toys in the doom universe.
Get raped master chief and plz keep yourself in the slow ass runspeed floaty ass newb jumping universe where you belong and stay the hell out of the skilled gaming realm where player run fast, can strafe and circle jump and know how to get the job done.
Maybe if it was five spartans against a single doom guy and all he had has melee weapons it would be a fair fight.. but even then the lame ass Spartans would still have to deal with actually hitting a target.
This would be the right time to inform you that the same goes for Master Chief. He's slower in the game. In canon, he's actually an effortless bullet-timer who run much faster than you experience in the game.