Speedrunning even stuff like MGS3 was basically just CQC ground throw everyone at full speed and do the binocular zoom/immediately switch to pistol for a guaranteed headshot trick. Then just lay down some magazines for the Eva escort.
This game you can go full on Sonic with D-Walker and a Shield, or even just run in on foot, wormhole a prisoner out and be done with it. But actually reconning and slowly choking out guards as you go the old fashioned way, along with a lot of other tools you can play around with, still provides a ton of options.
Variety in MGS games only ever rears it's head when you play the first time and mess up a lot, or just replay and do things unintentionally unorthodox in the least optimal manner just to troll AI guards and have fun. Or, as always, Infinity bandanna/wig and get crazy with it.