It may work out that way....and then it may not at all, but I don't think that would automatically prove the UA is inferior.
I know you have a bunch of other pres, and your tracks usually sound good, so those other pres are working for you. The UA, to you, may just fit right in there with them tone/sound-wise and nothing more outstanding...though that doesn't necessarily paint a clear picture which is "better" or more valuable in your recording sessions.
Often, in a shootout, the pre or mic that has that crisp/clear top-end, and fat but not tubby low-end will stand out and appear to be the better one in a basic A/B/C/D shootout...but then during various sessions, you might prefer the one that had the softer top-end and/or maybe fuller low end or bolder mids....etc
I have a bunch of decent pres, and I've done the A/B/C/D thing, and the most that I could ascertain was that they all sounded...different.
Comparing them purely by their dollar cost per preamp channel...the most expensive one is not the one I use the most, but I know why it is a little more expensive than the others, and when I do use it for the right situation, it shines.
I think that was the point being made in that quote I posted from the 3D Audio Preamp shootout....that you need a bunch of preamps, as opposed to looking for that one "perfect/best" preamp, like some newbs tend to do when shopping for gear....and often they feel underwhelmed, because of great expectations.
AFA you shootout...have fun, post up the clips, it should be interesting....but it will still be 100% subjective in the end when folks pick their faves....I'm sure you know.
In the clips that John Watkins posted, I liked the sound of the Avalon the most, because it was a little more meatier, but the ART MPA was very nice sounding...and the UA was a surprise next to them, but the UA has that fat/thick/woolly sound, and I'm sure on some other sources, it could very well be the best choice instead of the Avalon or MPA.
Lots of mics...lots of pres....that's the ticket.