These two authors represent two very different positions on a continuum of style.
Let's look at a sample of Hemingway's prose first:
Manuel drank his brandy. He felt sleepy himself. It was too hot to go out into the town. Besides there was nothing to do. He wanted to see Zurito. He would go to sleep while he waited.
Sounds a bit like the aluminum paragraph, doesn't it? As developing students of style, let's make a couple of descriptive statements about it. First we can say that Hemingway doesn't do much embedding; there is only one relative clause ("while he waited") and not much in the way of embedded phrases. There is a technical term for sticking to main clauses: parataxis, which roughly translates as "beside . . . structure"; that is, the main clauses line up side by side.
We can also say that the Hemingway passage tends not to link sentence units via "and" or other transitional phrases. They're disconnected, standing off by themselves. There's also a word for this: asyndeton, which roughly means "no . . . connection."
So, we can describe Hemingway's style here as "paratactic asyndeton" (or, if you prefer, asyndetic parataxis).
Now let's ask the "so what?" question. What's significant about what we've just said?
The fact that Hemingway hasn't connected his sentences (or s-constituents) could mean:
(1) He doesn't think that they are connected. If, for example, one didn't think that there was a webwork of meaning operating in the universe, one might not present such connectedness in one's writing.
(2) He is too tired to make the connections. Is this the anomie of the so-called Lost Generation?
(3) He doesn't believe it is the author's responsibility to make the connections. Instead he places the data out there for the reader to connect.
For whatever reasons, Hemingway has selected his sentences and made editorial decisions about how to construct them and how to place them in relationship to each other. And he has done so in a way quite different from William Faulkner. Here is a sample of Faulkner's prose:
He did not feel weak, he was merely luxuriating in that supremely gutful lassitude of convalescence in which time, hurry, doing, did not exist, the accumulating seconds and minutes and hours to which it its well state the body is slave both waking and sleeping, now reversed and time now the lip-server and mendicant to the body's pleasure instead of the body thrall to time's headlong course.
Hmmm. Another description of someone who is tired. This time, however, we have a presentation which fully compresses and connects the data. Faulkner is noted for this kind of writing. His sentences can go on for more than a page apiece.
Faulkner's passage does two things that Hemingway's does not. For one thing, he makes connections. Generally, we describe Faulkner's writing as being "polysyndetic" (poly = many). He also ranks his s-constituents via subordination. His complex sentence structure establishes a hierarchy of meaning. Therefore, we can say that his writing is characterized by "hypotaxis." The hypo- ("under") suggests the ranking of the information vertically, at different levels of importance. Some information goes into main clauses, other information into subordinate clauses or phrases.
So, we can describe Faulkner's style here as "hypotactic polysyndeton" (or, if you prefer, polysyndetic hypotaxis).
The difference from Hemingway? We could suggest that:
(1) Faulkner believes that there is a pattern of meaning in the universe and that he is able to interpret it.
(2) He believes it is the author's rule to establish this meaning for the reader. (We will gloss over Faulkner's alcoholism and the oft-noted suggestion that many great writers are neurotics who compensate for lack of control in their own life by creating imaginary worlds over which they have total, god-like power).
Another generalization that is often made about the parataxis/hypotaxis continuum is that parataxis is more masculine and assertive. Take Julius Caesar's paratactic "I came. I saw. I conquered," for example (or its variant in the film Ghostbusters: "I came. I saw. I kicked its ass."). A hypotactic version of Caesar's famous declaration might be "Since it was I who arrived and saw the lay of the land, victory followed as a matter of course." One hesitates to call this "feminine" but it is closer to academic writing, which analyzes propositions and establishes a pattern of explicit meaning (here, it's causality).
Ask yourself whether parataxis or hypotaxis or some blend of the two is right for you. As you can see, there are worlds at stake.
If nothing else, it's worth noting that readers tend to associate academic writing with hypotaxis. I have also seen it advised that in such writing, roughly 1/3 of your clauses should be subordinate.