Although I don't use them in Safari and it's not automatic, but you can
move (non-History) bookmarks in to any order you want, manually. OTOH, I've never had to sort them by anything, anyway. All mine are named the way and with the words I want, not necessarily the site/page name. Seems an arbitrary way to do things, IMHO. Perhaps there is a pref for how one wants them sorted or even
not? And I would assume that any browser would allow editing a bookmark, also. At least the displayed name...
Sorted the way you want, even if done manually, is a big benefit of having bookmarks in a different app than the browser; they're always in the same order, no matter what browser one happens to be using/testing.