The ranking system is garbage in this for sure. Its based on speed more than anything. I know they tried to broaden the range on what is truly vital on an infiltration mission. Some would argue getting the job done quickly and efficiently is preferred to taking your time meticulously taking out guards like a ghost. Seems this game rewards you for being loud.
I agree the scoring system is strange and frequently inconsistent. They did not change what's "truly vital" though, because speed doesn't necessarily equate to lethality or unwanted attention.
If you're meticulously taking out guards... evaluate who you need to remove. Just take more chances in general. All those times where you end up going "I probably could have gone," just GO. If you plan a decent approach, you can almost ALWAYS retreat and recover. If you're quick-but-careful, a minor fuck-up is -- at worst -- an opportunity to lure the investigators into terms of your choosing.
Yes, speed is heavily rewarded... on top of any other goals, and often equal to the sum of them. And it should be, because doing the same thing faster, is objectively better. Points are not awarded for sincerity: they are more or less tied to demonstrations of skill, and the amount of risk you take. That is to say, how much you accomplish, how quickly and cleanly.
Half measures do not and will not get rewarded. At all. Ever. The only way to pull a decent score with them is to concentrate on a speedy operation... at which point it's not a half measure.
If you refuse to go quick, then double down and do
actual "ghosting," for a more-or-less a sure-thing S-Rank. Or step it up, and literally do everything and ambush everyone... which is no guarantee, but a good start for a strong score. You don't need to be super-fast if you're very thorough, but you must be "not slow."
Not to say the majority impressions of the scoring and open world are off-base. There is a lot of truth to them. But based on what I generally hear and read, there's pretty standard advice on how to "deal with it" and even wrangle more fun out of the game.
Set goals. Do more, or faster, or less to do the same thing, or embrace overkill. Spend less time on set-up to have more fun in the heat of the moment. Or spend more, and revel in complete tactical and situational superiority.
Stop ACC'ing. Lurk and terrorize the map until the whole thing's red and you stink like an abattoir that just hit puberty. Plan chains of ops around priority, travel-time, and (optionally) maximum disruption. When you think "do I have what I need to do this," say "yes" more often. If the answer is
really "no" then think "then what can I do" and "can doing that, help me do this."
If things go south, and you're left with a mess... then fuck it, don't put in more effort to get a lower score. Don't go loud and lethal if it's too late, or if you just don't want to. Blow your C4, high-tail it, and chuck a few grenades at any Nice Things you see on your way back out.
This all plays into the overlooked facets of the open, semi-persistent world. Things like retreating, or softening targets, that are complete no-brainers sometimes, but just plain fucking
absent from 99.9% of games with direct control. Maybe 10% "allow" some (mostly pointless) recon from afar.
Here that stuff's pretty much required. You can even come by DEEP recon fairly honestly, which is a rare thing indeed. And information and preparation can make or break a clean, high-scoring run.
Not to the extent where you have to spend half an hour circling and marking, until you ruin the game for yourself. Unless that's what you get off on, in which case it's totally valid, viable, and rewarded... as long as you use that information to make up for lost time.
I have loved games that are more broken or repetitive, for lesser reasons.
This is the Codex, so you probably have too.