You seem to be thinking a lot lately about being able to measure how good someone is at PvE. But it's not going to work when you have one person who is amazing at stuff that involves interacting with the environment/ interrupts etc but can't get the pinpoint timing that you'd need to max dps output, or vice versa. Or someone who is a decent player but gets very very very stressed if they are asked to perform a raid-critical task.
Let's say that a good DPS player has four tasks:
- Maximize DPS output
- Utility Stuff
Further, let's say that you can measure the individuals performance on a scale of 1 to 10, with 10 being best.
If I am reading Spinks correctly, she believes that performance of these tasks are independent. That performance in one task is not indicative of performance in a different task. That you could have a player who is a 10 at maximizing DPS output, but a 4 at interrupting.
In my experience, this is not the case. Performance of the tasks is correlated. Scores for an individual will cluster around the same point. A really good player might have stats of 10,9,9,8. An average player might be 6,7,7,5.
Now, performance is not absolute and innate. Things require practice. If you never interrupt, then you'll probably require some attempts to get the hang of it. You can move all your scores up by learning new techniques and practicing more.
But in my experience, good players are good players along all dimensions. If they show skill in one task, they can pull their performance in all the other tasks to the same level.