Yeah but what was left of those soldiers died on Okinawa, the remaining Japanese Army was not as tenacious as what the US encountered on Guadalcanal and Iwo. They had no airplanes, fuel, vehicles, bullets or rifles. Japan was incapable of even mounting a resistance against the 1940's American war machine.
Also, when you task 22,000 soldiers to defend a tiny island its a lot easier than having the same number defend all of mainland Japan. If there was a pocket of fanatical resistance we could just bomb the tar out of it and go around. If you really look at it, Japan would've surrendered in the time it took our tanks to drive from one end of the island to the other. Maybe you would have roughly the same number dead as in Hiroshima and Nagasaki, but you wouldn't have opened the whole can of worms that is nuclear warfare.