With the following:
(setq org-agenda-sorting-strategy '((agenda time-up deadline-down scheduled-down habit-down priority-down category-keep)
(todo priority-down category-keep)
(tags priority-down category-keep)
The `time-up` is correctly shown first; however, all scheduled items are shown next as opposed to all deadline items (the order should be the other way around).
Also, it is unfortunate that there is no symbol for upcoming deadline items to differentiate them from past deadline items. Since they are considered "earliest", the sorting goes from "In 5 days... -> In 3 days... -> 2 days ago --> 4 days ago", which is rarely useful. There is no way to sort just items past due date "2 days ago --> 4 days ago --> 5 days ago", which is a much more common workflow (e.g. looking down the agenda, the more salvageable recent deadline items are at the top). It is more sensible to just limit deadline items to items due today or the past, and have a separate symbol for upcoming deadlines (i.e. "upcoming-deadline-down" and "upcoming-deadline-up"). Then, one can e.g. put all upcoming deadline items at the bottom of the agenda because he wants to deal with items that are more relevant now.
Currently on lorg-mode 9.3.1 (latest version of org-mode available as of this submission).