The reader should not have to reverse-engineer the sentence
Good prose does not mean every sentence is short. It means the reader can understand the intended relationship among its parts without repeated parsing.
A useful target is one-reading comprehension. An intelligent reader should usually be able to move through the sentence once and know what modifies what, what caused what, and what matters.
Prefer ordinary words when precision is equal
Your Zinsser and Paul Graham notes converge here. If "use" says what you mean, "utilise" rarely improves it. If "help" is accurate, "facilitate" may only add distance.
The rule is not "small words are morally better." Technical language can be the most precise language. The test is whether the longer or more specialised word carries information the ordinary word does not.
Concrete nouns and verbs do more work than abstract decoration
Compare:
"There was a significant deterioration in operational responsiveness."
with:
"Supervisors took two days longer to correct attendance exceptions."
The second sentence is not better because it is shorter. It is better because it names an actor, action, unit, and outcome.
Numbers often replace adjectives. Dates replace "recently." Named actions replace "issues."
Active voice is a tool, not a religion
Use active voice when the actor matters:
"The supervisor changed the roster."
Use passive voice when the actor is unknown or irrelevant, or when the paragraph is tracking the object:
"The roster was changed before payroll closed."
A rigid ban on passive voice can damage coherence. The sentence subject should often be whatever the reader needs to keep tracking.
Conditions should be easy to attach to the right claim
If a rule applies only under a condition, place the condition where the reader cannot miss what it governs.
Harder:
"The process can be automated with manual review when exceptions exceed the threshold."
Clearer:
"When exceptions exceed the threshold, route them to manual review; automate the rest."
The improvement is structural, not cosmetic.
Pronouns save words and create ambiguity
When "it," "this," "they," or "that" could point to more than one noun or idea, repeat the noun. Elegant variation matters less than unambiguous reference.