It is sound, as long as you are allowed to tune it with "constants" that aren't and "variables" that won't. Why the mass hierarchy? And three generations (now

It is sound, as long as you are allowed to tune it with "constants" that aren't and "variables" that won't. Why the mass hierarchy? And three generations (now that is odd...)? All that just to ignore gravity? Given some tuning parameters, any formula can be made to be a model accurate enough.