I honestly do not mean to sound argumentative and I honestly think we are saying some of the same things just looking at them from opposite sides kind of thing.
Are you saying that in the OP original question that a 19" tire is "better" in sand?
That goes against what Woody, Jimmy Lewis, all conventional race bikes heavy or light, and most posters here are saying.
I am very much in agreement with you if you are saying that BP "should" run a 19" on his bike for his intended uses. But NOT in agreement if the arguement is that a fatter 19" is just as good or better in soft dirt applications which is all that the OP question was.
Feels like we have 2 different threads sort of.
it is easier to ask for forgiveness than permission