Ok, I can buy that, but that certainly looks to me like Sanborn didn’t think it was a velocity issue either. He is adding oil at the number 2 end of the gallery and has the crossover taking oil from between the 2 and 4 cylinders and putting it back in at between 3 and 5.
Which means he’s blocked the oil feed to the drivers side at the main bearing or someplace and is feeding the drivers side off the crossover.