Back to the OP:
Which option worked best for you or you wish :
1) long rows of din mounted components
2) short rows with segmentation of parts plated together. Breakers and coils on a rail. All power on another.
3) I just went for it and it worked
I have a relatively large panel at 24x18x8. Just for the the components on the backplane - the power comes in from the inlet flange at the bottom left. Used left instead of right because it is a shorter distance and I cross fewer lines and hoses. From there to the distribution blocks that are vertically mounted. From the bottom up - Ground and neutral, then across the top to Hot1 and Hot2. The Hot1 and Hot2 DIN distribution blocks are horizontal across the top. Power then flows from there down to the breakers, then Hot1 goes to contactors and Hot2 goes to a 120v distribution block and the SSR's to the element contactors.
From the element contactors then to the element outlets.
All switch buttons, alarms, and PIDs are then wired from the front panel to the components and 120v dist block.