The sad truth is that with this kind of mismatch there really is no way to avoid a little humiliation. The kindest thing would be to have an automatic game determination if any team scores over (lets say seven runs ) the first time at bat before even one out is made. Then we call these games early and the losing team still has to live with it. After this technical knock out, the winning team could put their second and third team players and play another four innings for fun.
In my day we ran cross country with one of the top coaches in the country. While most schools ran one to two mile workouts a day, this coach had his kids running 6 to 10 miles a day. (This worried many parents back then but is common today.) In cross country you can run as many kids as you want, but only the first five finishers count for the team. We had races where every one of our school (like 25 kids) beat the best runner at the other school. Sometimes with a long wait before the other runner came in. It must have been humiliating, and the coach had few friends in the league, but our team was very pleased with the results. I remember one race where the other coach was cautioning his runners not to try to start out with us for fear they would not make it to the finish line. What can you do? I say the losers should congratulate the winners and make it a lesson in character building.
THe difference there is that running is an individual sport, and even more important is a sport where you compete against a clock. Sure, it may be a bit humiliating to have a bunch of other runners come in before you, but you already know what your best time is, and you already know how many kids in the world can run much faster than you, so the humiliation is just that it is made obvious.
Your running faster than all the other kids didn't in any way make them run slower, or keep them from being able to run the entire race.
So in many ways it is different than a softball game where if the other team runs up the score you don't get a chance to bat.