Not altogether a bad idea.
Certain sound qualities COULD be listed/graphed like “harsh” “airy” “balanced” muffled, lacking mids, etc and some kind of chart made reflecting general consensus of certain MANUFACTURER’s tubes, but that’s the problem comparing, say, an EL34 made by the same company just years apart or across a spectrum of manufacturers. Components/assembly techniques change as does sound.
I’ve often wondered if the same kind of LASER or X-Ray spectroscopy techniques used on, say, the Mars Rover or by the team at Oak Island could give better data on materials used with original, pre-1950’s tubes most/many of us seem to enjoy listening to and those data used to compound alloys virtually identical to OEM Western Electric 300b tubes for example.
I haven’t read of any companies actually doing this sort of metallurgical analysis although I suspect the formulas/recipes are public domain by now.
One still sees older WE 300b tubes selling for THOUSANDS of dollars when a slightly used new mfr. pair can be had - second hand - for as little as $750 on ePay, $1500 new with 5 year warranty from mfr.
But a comparison chart of “varietals” far too complex a problem unless taken with fewest pertinent qualities necessary to make sound judgments (pun intended).
YMMV.