Come on, dude, you are embarrassing the rest of us engineers!
But better you recognize this now on a comparatively trivial topic while shooting the sh!t than while engaged in a project that involves safety related design decisions.
When empirical evidence contradicts your understanding of theory, you don't double down, you start investigating ... because either your understanding of the theory is incomplete, the theory is actually wrong, or the empirical evidence is misrepresented/misinterpreted.
In this case I would consider the presence of MTM center speakers among every major manufacturer of speakers (designed by engineers, physicists, and others who specialize in acoustics and speaker design). Knowing that they carefully measure and listen to the result of their efforts makes for pretty compelling empirical evidence that MTM speakers are not a faux pas. Right off, I am having a tough time thinking of
any speaker company who avoids a MTM design for their center. That should give you pause!