Yeah, I have thought about account numbers as prefixes in the past as well (or some other syntactic hack for integrating the chart numbers into Ledger's account names) but didn't really try it.
A small shortcoming of Ledger in relation to this seems to be that it is not very comfortable to modify your initial accounts system later on, e.g. modify the hierarchy of things when you found some mistakes, etc. In the numbered chart of accounts system (which you have in a separate file, like PTA does), this seems easier.
I would also confirm that spotting accidental data entry errors is also easier in a single-line oriented journal like PTA. In Ledger, one entry consists of at least 3 lines, which is quite verbose.
Obviously, a more seasoned diy-accountant probably simply doesn't make any errors of this kind, or automates these tasks to an extent, so there's that. :)
Nonetheless, Ledger is obviously still a remarkable piece of software. I also recall some philosophically interesting blog posts by the author John Wiegley, on maths, thinking in general or something similar. He is obviously a brilliant mind.