As good as the Unreal Engine is. In terms of programming talent, i'd go with Carmack. There may have been other people that would have done for FPS the way carmack did, but the point is, he did it before anyone else. Ergo, he was ahead of everyone else. And unless he's been just twiddling his thumbs for the past 5 years, i doub't any single person would have caught up to him in terms of experience.
Actually, FarCry's was the second game i've seen that let's you headshot a mile away. The original one was MDK. MDK may be old but i have yet to find a game with a better sniping system =) Plus i can't even call MDK hitbox based since those 'hitboxes' are more like per polygon collision (hitboxes are scaled down versions of the actual models used), take a shot between the arm and chest and it's a guaranteed miss
I'd say MDK was well ahead of it's time.
BTW, who programmed wolfenstein 3D?