Help with the wall method please

I need a bit of help with the wall method of loading here. When you look at these pics imagine the totes sitting vertically in the van starting right behind the bulkhead. If someone could please tell me the order in which the bags should be loaded as in A = 9 etc etc for the first and second walls that would be great! I've tried to figure it out from some posts on here and a couple of youtube vid's but what's getting me is the way the totes are ordered on our U racks vs other stations so I'm not quite getting which order they should be stacked in.

First and second wall here: [https://imgur.com/a/ZqUERZl](https://imgur.com/a/ZqUERZl)

How U rack is loaded at our station in stop order: [https://imgur.com/a/6j5GyJE](https://imgur.com/a/6j5GyJE)

I've got the rest of the method such as making a shelf with a collapsed tote on the passenger seat for boxes and putting envelopes between the seats. Over flow in the back behind the walls organized by group. Thanks!!!