I have written at length about Jon White's poor math for putting together a morning line at SA. I'm not going to go over it once again, but I will say this -
I have reached the conclusion that it may be a conscious effort to increase handle.
When 60-70% of the horses you list go off at higher odds at post time, perhaps the betting public think they are actually getting good value when the M/L odds were much lower on their selection?
Or, most likely, he just doesn't have a clue about odds percentages.