Biggest problem with consolidating putter molds using Judges as the main pillar is that it's tough to find an OS judge - Lucid was as stable as Fuzion was as stable as Classic was as stable as Prime. You could probably pay $25 or so for some Lucid-X or moonshine specialty judge and cross your fingers.
Here's how I see it - choose your main putter based on what will save you putting strokes overall period. Then put a backup of the same mold in the bag for throwing. Then build the rest of your putter lineup around those two.
For example: You say you putted Crowns, so start with your favorite Crown for putting only. Put a Medium or Soft Crown in the bag too for throwing. If you feel like you need something more neutral, a Proxy or Pure goes in too. Zone is a no-brainer, so do you need something in between your Crown and Zone? Bag an Envy or Jawbreaker Zone if you have a worn one. As your thrower Crown beats in, it might overtake the Proxy slot, but if not, no biggie. Yeah you have multiple molds to juggle, but you've based your lineup on what saves you putting strokes, not on this vague idea of mold minimalism.
EDIT: alternatively pick up a stack of Wizards, put your head down and just lean HARD into mold minimalism for the sake of minimalism.