First of all, the .357
revolver/10mm
autoloader argument has always been stupid, not so much from the cartridge-vs.-cartridge perspective, but from the wheelgun vs. semiauto perspective.
That truly does make it "apples v. oranges," unless you equalize the platforms for testing purposes with
non-cherry-picked loads - say, by chronographing a full-power 180gn .357 load from a 4" S&W Model 28 against a full-power 180gn 10mm load from a 4" S&W Model 610 revolver. That's about as equal as you can make it ...
Or, with the "6 .357 Coonan autoloader, pair that against any 6" 10mm 1911 for comparing loads fired. At least you're using two 1911 platforms of equal barrel length to attempt to get to anything like a valid comparison.
As far as what might be called "ammo diversity," sure, a .357 wheelgun can shoot the .38 Special-Ed cartridge, but a 10mm Glock with aftermarket barrels (and, assuming the spare barrels are properly fitted, a 10mm 1911) can also shoot the .40S&W, .357Sig, and 9x25 Dillon cartridges.
So right there, the 10mm enjoys an overwhelming two-cartridge advantage over the poor .357.
QED ...