True, but it's likely that most of the cars from a given location would be either iced or mechanical. Blocking by car type, which is what I was referring to, would be minimal. Part of that was due to the fact that most of the shippers were set up to hand 40' reefers. The new mechanicals were usually at least 50', and small fruit warehouses either had to shift each car into position or skip every other warehouse door. In most cases even the "small" shippers in the Wenatchee area had multiple loading doors.
Blocking for destination, on the other hand, would certainly be needed, regardless of car type. "Appleyard" wasn't called that just to be cute. It's main purpose for years was collecting and blocking carloads of fruit. And, yes, it had a large icing facility right to the end of ice service. I wouldn't be a bit surprised if a reefer block destined for, say, New York City, would have the iced cars together, and then the mechanicals. The GN would let whoever delivered the cars switch them by customer.