That thread was missing bits, so here's a new version:
This is my largest modular build, a Pittsburgh Modular EP-420 with three rows of 140HP. This is often supplemented by a 104HP skiff and some other semi-modular synthesizers, but this is my main rig. Now, this is how I approach module placement and overall layout. Your mileage may vary.
Top row, red: Oscillators. Main sound sources. Other oscillators (Plaits, Dixie, BIA) get dropped into that 104HP skiff when I need them. Simple.
Middle row, yellow: Primary modulation sources and utilities. At eye level where I can find them quickly. Arranged by where they sit within my workflow.
Middle row, pink: VCA's. Leftmost VCA is often used to bring in outside signals from my Moog stack or that 104HP skiff.
Middle row, green: Effects and sound sculpting. Reverbs, delays, compression and EQ. End of chain stuff.
Bottom row, blue: Filters. I like to ping and play my filters, so they are where I can reach them easily.
Bottom row, orange: Popular stuff. Interactive things. Modules I reach for often or that want a lot of hands-on attention.
Once oscillators are chosen, overall movement is from lower left to top right, ending with Make Noise XOH to a sound interface. This layout really works for me. I know where everything is at. I can reach things that are most important to me. Developing muscle memory is easier when the landscape makes sense.
Hope this helps!