you just don't know unless you try it to see/hear/experience advantages and disadvantages for yourself. all of the naysayers (there will be naysayers!

) haven't tried the combination you're thinking about, in your context, yada yada. so they cannot possibly know how it will sound to
you. (make sure your cab combinations are figuring impedances and phase correctly.)
lots of folks here are pairing two cabs (different size cab, different size driver) successfully --- as would be expected with competent cabs. they just don't brag about the results on TB because of the herd-bias-protocols. IME: you'd have to be pretty unlucky to pair a 12"/cab with a 10"/cab and not get something useful.
if you try it: you'll be obligated to get back to us for a review! you could change the herd-view/herd-speak forever!
(or not!) good luck!
FWIW: i have access to many different cabs with all of the expected driver sizes scattered among the cabs (PA). i have never paired a disparate combination of cabs with results which i didn't expect or that was not useful = any two cabs worked fine together: some combinations had distinct advantages, some combinations had a few disadvantages (e.g., size of stack/weight) --- but all combinations were able to deliver an expected, useful outcome (usually i wanted more volume with more lows, but some combinations got me great midbass, or great mids, etc.).