4-layer Stacker 4x12 to 1x12 via 2x2p

Does three stacks to make a 4-layer shape. 3x12 inputs are sorted by level so the top level of all three are the same shape; same with other levels. Then the fourth full input, 1x12, has the layer-4 shape in all three levels. The 1x12 output goes to the bottom of the 2x2p. It uses what I think is an odd arrangement of stackers. You decide. I have a sorter for the 3x12 inputs to change them from three 1x12 inputs to 3x12 sorted input. It's also possible to build the layers 1/3rd at a time and output them to a single level so all the inputs are already sorted (avoids the 4 PU sorter 1x2p).