I think you should choose by not other peoples standards but by your own.
Lots of recordings around if you dont want to actually get up and test them, like
https://www.wavetable.nl/category/comparisons/, http://www.amoretro.de/soundkarten-und-wavetable-recordings, and Youtube is chock full of MIDI recordings https://www.youtube.com/@trizeptorx6566/videos
MIDI playback is incredibly hit and miss on a technical level AND even "good results" can be rather subjective. Yes, generally Roland and Yamaha will be top tier, and rarely if ever will they mess up a song, but sometimes they do get outclassed. And lot of times random other MIDI modules sound so different you would think its a completely new piece of music (the controller failed to interpret the instrument - volume - effects properly, or its samples were not proper for the intended use, still the output is suprisingly listenable, and the module fails successfully).
Like Reptile Paradise Cancun FX frequently out-Rolands Roland cards, Korg AI2 cards destroy competition in guitar and rock heavy music, Turtle Beach RIO sounds so psychedelic it plays completely different soundtracks, and Miditemp DOX-1 and Roland SD-50 that either sound bad because of missing a decent GM mode, or sound absolutely stunning, like a lightyear ahead AdvancedHD version of Korg and Roland modules, that make period correct stuff sound like childrens toys in comparison.
Personally i would keep the Roland SCB-55(since its a better version of the SCB-7), Yamaha DB50XG, and Diamond 4MB(since it should be basically a TB Cancun/Serdaco Yucatan FX), and would try to trade the others for a Korg, or something you find decent.
the loyal slave learns to love the lash