2 melee 2 ranged standard

[Galvuu]

My apologies on the quartile analysis! Your numbers look correct. However, there are some things I take issue with here:

The whole team does not have to perform well for you to parse well. It can help, of course. But in some cases, the whole team doing well actually hurts you because it can get you a worse kill time. I've had many parses this tier where I get a 99 while the rest of the team is doing blues and greens because they delayed the kill time to the end of burst, so that isn't necessarily true. You can still do well without a whole team.

It really depends- I think a good point of comparison for PCT is ShB NIN. Because they're both very bursty jobs with high rdps/cdps and with a powerful raid buff. The multiplicative nature of raid buffs and how much PCT gains from them all stacking both in terms of adps (due to his burst) and getting rdps contribution from others (by putting their burst in their strong raid dps steroid) is very significant. So what you're saying is true- I've had oranges (and even pinks) with drifting buffs or people with weakness on the 2 min burst... but it was honestly because I crit a lot in burst myself. I've hard many runs (like... 95% of my runs) where I play as well as I can (better than many high oranges/pinks) but I get a purple because my team's buffs drifted/they died/I didn't crit. It's really out of my control. I can see an argument for the 95% performance to be considered, but I'd still weight it far lower than the 90% (and also the 80%). This was the case with ShB NIN too- your crit in opener and party bursting properly was a massive factor on your own performance and it was mostly out of your hands.

Think about fighting games for a second. The "best character in the game" for a midcore player and a hardcore player will be very different. A brand new player might find the "best character in the game" useless because they are hard to play. But they are still the best character in the game, regardless, and should be balanced as such. Midcore player's concerns should not be ignored, but when players are not using the tools in the game, how can their opinions o the balance of these tools be said to matter as much as the players that are? It's a tricky balancing act, but you can't ignore the top anymore than you can ignore the bottom.

My mental model for this is League, actually. I'm a ranked soloq player, basically. I know pro play exists and needs some balance, but it's very far-removed from the average player's experience. "Midcore concerns" (borrowing your expression here, but it illustrates the point well) become more important because the game is a cooperative element- you end up paired with these players, so now their contribution affects your gameplay/experience a lot and it's totally out of your hands. XIV leans even farther into the "midcore" part because it's purely cooperative (no pvp)- a big departure from the fighting game hypothetical. Ofc, if there was a job that did 20% more cdps when played to its maximum (both individually and in the team), that'd be a huge issue. But PCT isn't close to that. I'd say, perhaps a bit coldly, that I'm happier ignoring the bottom (if you don't press buttons, nothing really matters). I want to add the addendum that I'm not advocating for simplifying jobs to appease the lowest common denominator (something XIV has been doing as of late), but I actually think PCT's reward for high mastery and overall team performance is adequate. I wish more jobs were like that.
(Strictly speaking, BLM is... but in the worst way possible with miserable payoff)

(Sorry for being harsh-spoken at times, I appreciate the civility. I hope I'm getting my point across. Fwiw, while I have strong conviction in what I'm saying, but I can be convinced... it's just that I've played the game a long time, and I remember when 5.2 SMN was overpowered, and PCT isn't at that level at all)

EDIT: another thought that crossed my mind, I think the extreme numbers might be a bit better because, atm, 99% of NMs are random df groups, while extremes are a bit more planned for/filtered, and probably reflect the Savage/static experience more closely.