So it is possible to have multiple drive sizes on a single rail. The set includes a rail for each of the three drive sizes.
Mixed Drive Socket Holder Storage Rails with Rotating Clips + Magnetic Base 3pc
80pc Socket Rail Tray Red 1/4" 3/8" & 1/2" Sq Drive Socket Holder CT0736
3/8" Drive Socket Holder Vertical Tray 3 Tier 45 Pce Green Boxo B-38VERT3-G
3/8" Drive Socket Holder Vertical Tray 3 Tier 45 Pce Red Boxo B-38VERT3-R
Sealey Premier Tools SH1414HV 1/4" Drive Socket Holder Rail 4-15mm Hi-Vis
Sealey Premier SH3815 3/8" Drive Socket Holder Rail 6-21mm