I had a similar issue recently, with the movie “Mask” (1985 - Cher - Sam Elliott)
Even though the filename was clearly set as Mask (1985).mkv,
Plex kept identifying it as Mask (2013), and applying the wrong poster, etc.
Doing a “fix match”, and selecting the proper movie did nothing;
it stubbornly refused to change the poster, or any of the details.
I was curious at that point, so tried a number of “fixes” for it.
Manually editing the “Original Date”, and locking it in caused
an immediate, spot-on match, but I shouldn’t have to do that,
since the correct year is in the title of the folder, and the file name.
I twiddled around with it for a bit, even going so far as to using
an MKV editor on it, and populating names and dates in the MKV headers.
After that, a re-scan of the library caused it to become merged
with The Mask (1994 - Jim Carrey) for reasons unknown.
I unmatched them, KO’d the Mask (1985).mkv file,
re-scanned the library. . . then copied the file back into
the movie directory, and did another scan.
This time, as I watched it on-screen, it briefly displayed a
thumbnail of a scene from the movie itself, flipped around,
and for a brief moment, showed the correct poster for the movie,
then flipped back over to the thumbnail scene from the movie.
I went in to edit, to the posters section.
It had several possible posters from the 1985 movie that were correct,
as well as one poster from a 2013 movie. . . and one poster from “The Mask”,
neither of which were correct.
Arrgh.
So. . . one more time. . . delete the file, re-scan.
This time, I took the added step of deleting the bundles,
and emptying the trash.
I put the movie back in, and waited for the library to update.
It scanned, showed the movie thumbnail. . . and stopped there.
Hmmm. Why no poster?
I opened up posters. . .and this time, only the correct posters
for the movie were visible. . . AND there was a check-mark on
the first poster. . . but that was not what it was displaying.
So, I re-selected the first poster, hit save, and called it a day.
But, it was definitely more work than it ever needed to be,
and still not really resolved to my satisfaction,
but I didn’t want to spend any more time on it.
Curiously, I noted that if I un-matched the movie, I would have expected
its image to revert back to a plex-generated thumbnail of the content,
but, in my case, it kept flipping the thumbnail back to the same (wrong) poster.
As for the actual matching process, I agree - exact matches should take precedence.
Obviously, there are some other factors involved in computing the score.
Example - “No Country for Old Men (2007)” comes back with a score of 99.
Why 99? What is the missing piece of the puzzle? Surely not another movie
of the same name – let alone in the same year.
Exact matches (Title, and year) should come back as 100%,
unless there is more than one movie with the same name released that year.
Then I would expect to see multiple matches with identical 100% scores,
along with something that would allow the user to disambiguate the two.
“Fast & Furious” is close enough to “Fast and Furious”
to return an identical score rating for match purposes.
Likewise, any decent search engine should be able to determine that
“The Bells of St Marys” is reasonably equivalent to “The Bells of Saint Mary’s”,
and return a high-probability match - certainly higher than “The Bells of Saint John”.
But, who knows. . . 'tis a mad, mad world we live in. 
