Hi dp,
If I had your interest in Foundrys, I would have a group “Foundrys” folder with a sub folder for each Foundry, then just place the fonts wherever they belong without more folders. That will save you a ton of folder space. You may have to break a few folders down into subfolders A-F, G-L, etc.
As for your Actual Fonts, (if you HAVE to keep extra font folder information, do it in a zip file somewhere else) use Alpha-Numeric folders, “E:/Fonts/Aa-Ad” or whatever your Total Collection requires to keep the number below 1,000 - 5,000 fonts per folder. That will allow you to eliminate “dupes” and quickly find your font if you can remember the first letter of the name but not the foundry. Be sure to make a CD backup!
Finally, (and for me, Most Importantly) I’d use Font Creator to add Panose information to any font that did not have it so you could find any style of font without having to put them in any special group categories to sort for them. See: