Here is my loose rendering of a hokku by Issa:
The autumn mountains;
On one after another
That offers a good example of how the common pattern — setting/subject/action — varies.
In this verse, the setting is the autumn mountains.
The subject is evening.
The action is … falls on one after another. But of course it is not written that way. Instead “on one after another” is the second line, and the verb “falls” comes right after the subject “evening” in the third line.
So the setting, subject, and action do not have to be in a rigidly divided sequence. Hokku is not that restrictive. And of course the setting/subject/action pattern is just a tool — an aid to writing hokku — but it is a very good and useful tool.