One of the basic rules of a sentence, NOWADAYS, is that it has to be understandable. You are not writing the Declaration of Independence, books are common, and no one has the patience to work hard to understand any sentence. And they should not have to.
Clark does a lot of long sentences. To me, they are very similar in style to Dickens -- the sentences are (probably) grammatical, but they are too long and complicated to be understood that way. But there is no problem understanding Clark's sentences using Sequential Phrase Grammar.
Her husband, Joe Stone, was in his office at the opposite end of the building, a pair of matching Persian rugs and a long hallway of beaten oak boards distant, his door shut, their sweet cur dog, Brownie, probably dozing tail to snout on a chamois pad beside the heat vent, and Joe was no doubt explaining every boilerplate detail of the umpteenth will he'd prepared for his mercurial, crackpot client Littie Pauline VanSandt, who, only a few minutes ago, had tracked red mud across the nice carpets and into his office, heedless as always.
When I write a long sentence, I use simple grammar. I am not saying this proudly, it is just my style. It makes the sentence easy to read, even if it is long.
They react again to the blood licking. Savannah leaves, Phil is putting his head between his legs, we start getting more screaming, Mr. Samuelson is sitting down and has turned white, "Ewwww's" have joined into the emotional symphony playing in the room, and Larry is shouting that he's a vampire and wants to suck my blood.
This is Salman Rushdie in a much longer, and slightly more complicated sentence. But the underlying grammar is not too difficult.
When he claimed to admire the city's powerful gangs for the thrilling casual potency of their violence and the tag artists for their transient encrypted graffiti; when he praised the earthquakes for their majesty and the landslides for their reproof to humn vanity; when with no apparent irony he celebrated the junk food of America and waxed lyrical about the new banality of diet cola; when he admired the strip malls for their neon and the chain stores for thier ubiquity; when he declined to criticize the produce on sale in the farmers' markets, the visually delightful apples that tasted like cotton puffs, the bananas made of pulped paper, the odorless flowers, calling them symbols of the inevitable triumph of illusion over reality that was the single most obvious truth about the history of the human race; when he, who had been a model of probity in his own public (though not sexual) life, admitted to secret feelings of admiration fo the corrupt local offical because of the flamboyant daring of his corrpution and, contradicting himself, cynically lauded a second corrupt local official for the sneaky, decade-long subtlety of this crimes, then India began to see that in the depths of the old age whose effects he had so heroically concealed, even from her, he had lost his hold on joy, and that failure had eaten at him from within, eroding his ability to discriminate and to make moral judgments, and if things continued to deteriorate along these lines, he would eventually become incapable of making any choices at all, restaurant menus would become mysteries to him, and even the choice between getting out of bed in the morning and spending the daylight hours between the sheets would be impossible to make.
In sequential phrases, there is no need to stay on topic. That can give long sentences a rambling feel. From John Green's The Fault in Our Stars:
They [her parents] met in the Peace Corps in Papua New Guinea, and so whenever anything happened there, even something terrible, it was like all of a sudden they were not large sedentary creatures, but the young and idealistic and self-sufficient and rugged people they had once been, and their rapture was such that they didn't even glance over at me as I ate faster than I'd ever eaten, transmitting items from my plate into my mouth with a speed and ferocity that left me quite out of breath, which of course made me worry that my lungs were again swimming in a rising pool of fluid.