CURRENT: 
I use numbering system only for my notes, 2 folders deep. Top directory have from 0 to 9 and and each one there is maximum 10 folders from 00 to 09, the next one 10 to 19 and so on, that makes maximum for 99 possible folders. Its a PKM (Personal Knowledge System) and the topics are sorted into the folders according to the DDC (Dewey Decimal System) List of Dewey Decimal classes - Wikiwand.
In the DDC the numbering spaces is theretically endless (123.456…) The notes app uses heavy interlinking and search so i dont need to manage the folders a lot.
FUTURE:
The plan is at some point to integrate numbering into my file system. The file system has however much bigger variety of content. And with lack of interlinking i would rely more on the folder structure.
OPTIONS:
JD gives theoretical maximum of 10,000 folders. If i would go the route, i would make it 2 folders deep. Main directory would have from 00 to 99 and each one their respective hundred folders.
In the website i did get why 10.12.53 would be too much on the brain. I also didnt get why random letters would be a problem. The positive side of number vs. letters is that most folders in our system as named using letters, not numbers, in case of most people (so in case you look for folder starting with JA… it would give you a person called Jack, so with numbers that would happen).
If i go and use letters anyway, with 3 letter system i could get maximum of 17 576 folders (26 letters in the alphabet) and with 4 letter system close to half million. compared to 10,000 of JD.
Letters system is used in LLC (Library of Congress Classification) Library of Congress Classification - Wikiwand
THE COMBINATION:
There also and option to combine numbers and letters, like in Hexadecimal Hexadecimal - Wikiwand where the number go from 0 to 9 and continue from A to F to a total of 16. If we would use the numbers and the entire alphabet, we would have 36 digits. So if we would have in the top directory 36 folder, with 36 in each one of them and a third level of 36 folders it would give theoretical maximum of 46 656 folders with each folder unique ID in the whole system from 000 to ZZZ.
Hope it wasnt confusing 
, its the simplied version with few factors left out left out.
EDIT:
In case i wasnt clear, im here to listen to critisism. Somebody needs to put a stop to this insanity. 
