I'd love to see snipers, trackers (i.e. people who aggressively hunt you even after an alert has ended, for instance, requiring you to set traps - I never did get to use those girly magazines!), marksmen (a cross between normal guards and snipers), commanders, maybe even bomb squads if you keep blowing stuff up and all that sort of thing in MGSV.
Yeah, I'm just surprised the strategy has never really changed beyond "figure out this guy's patrol route, then use it to get past him". If you trip an alarm, you will occasionally get a team dispatched carrying shields, but that is about it.
I think the series needs guards with goggles, who get a boosted line of sight. There could be scouts, who are lightly armed and armoured, can quickly call the attention of other guards, and have longer, irregular patrol routes, so they can surprise you. And officers, who can be interrogated to reveal the location of guards and pressured into calling off searches.
Oh, me too, so very much. I loved the camo thing but OctoCamo was a bit too oversimplified and easy. However this does bring up the question of how Snake can carry an inventory plus 10+ sets of complete camo fatigues! Another, similar thing I want to see return: disguises. Not just militia/rebel clothes as in MGS4 or scientist/engineer uniforms in MGS3, but also enemy soldier uniforms as in MGS2, complete with a requirement to carry their gear in order to not look suspicious. Maybe this requires a Hitman-style 'take clothes' option. Also ghillie suits.
Some creative licence should be taken, as it is a video game.
However, if we go in for realism, face camo could require you to first learn a pattern by finding it in the world. Then, you can colour it as you like, provided that you have enough in stock. Changing your camo depletes your reserve, but you can find more.
As for fatigues, your permanent inventory could hold one slot for fatigues, and a second slot in the disposable inventory for an alternative set. You need to pick which ones you want in advance. To craft new ones, you would need to find the recipie, and then scraps of material in the world. You can trade them in when you choose your inventory again, which saves the completed fatigues.