I can definitely sympathize with some of the concerns in this thread. Making the tranquilizer unsuppressed or removing it altogether would be far too stifling to the overall design, I think that's obvious, but this is still worth thinking about. I'm ok with it superseding standard weaponry, I treat lethality as a "just for fun" thing or a stress reliever/skill sharpener when I've already failed, and I think that's a fine way of handling it. MGS4 definitely had far more weapons than it needed, that I can agree on. In terms of balancing the tranquilizer, I really like the bullet drop Ground Zeroes added. The first person view shake is something I'm conflicted on, since it's a random factor, but the appeal is clear.
One thing I think shouldn't be ignored is the tranquilizer's potential as a distraction tool. It has better range than a magazine, but only works on some surfaces and has a different trajectory obviously. It still takes skill to use, and every shot you use as a distraction is one you aren't using to incapacitate an enemy, so there's interesting interplay there.
Maybe if the wakeup time was shortened and they raised the alarm afterwards? Maybe introduce a method of restraint so you have to tranq and then cuff/gag the enemy.
This is a very interesting idea, I imagine it working much like the "get down" command you can issue after holding an enemy up. I don't think having enemies initiate a caution phase after waking up or waking another enemy up would be problematic, can anyone think of a reason it would be, aside from generally making things tougher?
I might have gone off on a tangent, but I'm ultimately expressing my distaste for the grading system putting such a high emphasis on non-lethal weapons. I just find it absurd that the game rewards a dart to the head so much more than a bullet, and would rather the bonus points go toward successfully sneaking around the enemies rather than letting the player use magical, disappearing, amnesia-inducing darts.
Encouraging "no traces" play would be a great thing, I agree. The no weapons used challenge doesn't require you to be stealthy, which makes it pretty much a joke. Adding a challenge that doesn't allow you to interact with enemies outside of distractions would be great. Maybe even one that doesn't allow you to interact with them at all. This is all assuming that The Phantom Pain even has challenges at all, it's hard to imagine how that'll work in an open game structure!