You're over-thinking all this.
Very simply, having smaller, and thus faster, more articulate speakers, closer to your ears (near-fields), gives you a different type of response verses larger cones that are farther away (mid-fields or mains).
In my opinion, near-field monitors and mid-field or main monitors are two different types of tools. They each bring something different and important to the table.
Also, mid-field or main monitors churn up plenty of room sound, even in treated rooms, so they're going to be less accurate in general in various regards, unless perhaps you are truly in an ultra state-of-the-art situation.
Most pro studio guys will work with near-fields as well as mids or mains.... not just one or the other.
Personally I start out mixing with nearfields to get the mix into general shape. The accuracy of the nearfields allows you to really hear any issues that might exist, pops, clicks, bad edits, whatever. Also great for getting relative levels really dialed in. And ideal for assessing stereo image, phase, etc. Another plus, nearfields generally make for less ear fatigue.
Then when things start coming together I'll switch on mids or mains so I can start to "feel" whats going on as well as get a secondary portrayal of the overall frequency response.
In most cases I feel that the nears will show things that the mids or mains will not readily show, and vise-versa. So I feel that they're both important, at least if you're really fussy about dialing in a pristine mix that's going to translate well with minimal revisions. If you do it right in the mix room, you won't have to go back and forth to your car stereo 17 times etc.
So, in sum, it's not like mid or main monitors are "better" than nearfields. If anything, if I could only have one pair, I'd use good nearfields, regardless of room size etc, mainly because they're going to be more accurate overall and are really going to reveal whatever needs to be revealed. Again, mids or mains, depending, will not be as accurate and revealing to subtle issues. The may sound more flattering and "fun", but won't be as effective in terms of precision tweaking.
And after having said all this, I'll throw in that this is all actually very much a personal preference. No rules. I've seen guys working on tiny nearfields almost exclusively and other people working on large, very distant, inaccurate mains almost exclusively. Finally it comes down to whatever works best for the user. Room has a lot to do with it too.
One thing to remember, if you think you wish to rely largely on "distant" (midfield or main) monitors, the room REALLY needs to be treated VERY well. Like, not just throwing up some foam here and there, but should be put together by a pro designer, or at least user proper, proven materials and spend the time to do it right, measure, etc... otherwise your response will be terrible and inaccurate regardless of how great the speakers are.
On the other hand, good nearfields are more likely to yield excellent, accurate response even without going too bananas with room treatment... at least if the room isn't too small. Very simply, the closer the speakers are to your ears and the lower the overall volume, the less room issues you'll have. BUT, if the room is super small, you'll have no choice but to pay great attention to room treatment if you want to have a chance in hell of doing any degree of decent mixing.
Since you were studying cone sizes and distances... I'll mention that my nearfields are two-ways with 7" woofers and I keep them about 2.5" feet away from my ears, and my "far-fields" (if I may use that term

) are 3-ways and have 12" woofers and they're about maybe 9' away from my ears. And I soon plan on checking out other monitors too, considering something in-between, in addition... like maybe "midfields" with 10" woofers that would be about 6' from the ears. The hardest part would be getting them all into a proper sweet spot without having them block / shroud each other, this is the challenge that I have yet to figure out. Many people use more than two sets of monitors but almost always arrange them in a far from ideal manner... which kind of defeats the purpose.
Final statement... one thing I've learned that is not readily apparent when you first start out.... monitoring is ULTRA critical!!! You won't have any chance of doing even remotely decent work if you can't
hear what you're doing. A lot of guys starting out wind up spending all their dough on assorted outboard gear, lava lamps, etc, but yet think it's ok to use their old home stereo amp and stereo speakers for monitoring, even if temporary. Don't make that mistake. Good monitors (and proper monitor placement, meaning good stands, good room treatment, etc) should be at the top of your list. Just say NO to cheap, rigged monitoring. Get it right from the start, you'll be very thankful later.