I know its a bit late, but i never had a ps2, and after that skipped on 3 untill few days ago when i got an used ps3 with plenty of games.
I love how much MGS3 is over the top, with Ocelot meowing and such, but man do i miss crouch sneaking and over the shoulder aiming from MGS4
It’s not really built for that, but I think if you hold L1 while your weapon is held out in front of you, it will focus your aim horizontally toward the nearest enemy. Then fine tuning your shot in first person will be faster.