If you live in the world of Duke Nukem he's the same.
I think this is a good example of how Gordon is not the larger than life hero you claim.
Duke Nukem, in my mind, is unquestionably a one man army who rips off the heads of aliens and shits down their necks. He is a larger than life hero.
The Master Chief from Halo is a larger than life hero who single handedly saves humanity and likely the universe. At no point is there any doubt that this guy is going to kick the crap out of the enemy.
The sergeant in Doom is a bad ass, he continually beats down the forces of hell with his own 2 hands and a chainsaw!
But Gordon? LOL, he smashes crates with a crowbar and scampers around like a mouse in a maze. He's a wuss! The only reason he survives is because the aliens are retards who can't seem to kill one guy!
In fact you know what may make Gordon different from these guys is the lack of Larger than Life enemies. I don't recall gordon going into many battles where you felt, "Oh my god, I am so F-n Dead, everything he kills is pathetic, but with duke nukem you have seriously bad ass enemies bosses (from what I remember), in doom you have all time classic bosses, in Halo you have big ass things with huge guns.
Gordon is just an average schmo because the things he's doing are somewhat average, he shoots down flying things, he blows up striders, shoots insects to peices, and he blows up machines... But the other guys take out larger than life bosses and villians and that is what makes them better imo..