Is there measurement that correlates with cohesive/pinpoint imaging?

Certainly you are familiar with the two slit experiment, just model a mid and a tweeter on a large baffle and let it rip for a few cycles.

as for precision matching of drivers and pairs, that is a hallmark of Vandersteen for 20 plus some years now, I know they all go in the chamber for a filter tweak as well - the 7 are matched to .1 db as I recall
- the matched pair are delivered with the actual plots. Obviously an unsymmetrical room can present challenges, as Eric suggests some treatments might be appropriate and of course there are fans of DSP.
Of course this fanboy has other speakers that have positives as well: Quad ESL 63, Thiel 2.3+, Dynaco A-25, some Totems.... some tiny baffle Sonus Faber that throw a super big 2D image ....

rather than focus on hyper flat frequency response maybe measure the RT-60 of your room.....

measure and listen but always enjoy

Whenever a question arises, regarding sound stage and imaging; I make this suggestion: The following provide tests, with which one may determine whether their system actually images, or reproduces a sound stage, as recorded.      ie: The LEDR test tells what to expect, if your system performs well, before each segment.      On the Chesky sampler/test CD; David explains in detail, his position on the stage and distance from the mics, as he strikes a tambourine(Depth Test).      The Chesky CD contains a number of tests, in addition to the LEDR.    (https://www.audiocheck.net/audiotests_ledr.php )      and: (https://www.discogs.com/sell/release/2818064?ev=rb)      An article, in Stereophile, on the subject: (https://www.stereophile.com/features/772/index.html)      The LEDR eliminates the variables, far as what's on your source material (recording/miking methods, etc), when doing listening tests, in your room.

Why?

I'll vote with eric on this issue....
One can have outstanding equipment that still sounds like dreck.
Conversely, 'meh' can shine, given a sensitive set-up in the 'well-tempered' room....

Why? One asks..  HRTF in our 'real world'.
It IS what you hear, and most times, Where you are when listening to it.

I'm not a huge fan of the 'rooted to the floor' chair 'sweet spot'.
Generally, when @ a venue, hall, or an outdoor concert, having the 'best spot' to enjoy becomes a function of having the $ for the seats or the timing to place one's tush there.  So most times one gets to listen where one is...
In ones' home, set-up of the listening 'volume' becomes (imho) just another parameter of the items within it.
First reflections, room volume vs. base freq. and it's harmonics, 'live' vs. 'dead', eq or not to eq, spl low or high....on and anon....

Unless you were raised with your head in a foam ball and have 'virgin ears', unsullied by the wear 'n woe of uncivilization, it's a near given that your ears are not Perfect.

Therefore:  Your perception is Flawed.  So is Mine.  No 2 of us 'hear' exactly alike....unless your share a head with another body, and are pretty much on y'all's own.

If one must have the perfect listening experience, free from all of the variables noted above (which isn't complete...oh, no....)...

Buy the Best Isolation Headphones one might aspire to.
...and give it a break....

'Cheers', J