I would say 'copy-edit' — as in, when you say guru, if you mean someone who knows the subject matter that you want to make sure what you've written makes sense, is accurate, and isn't being overly wordy or assuming the reader knows something that may need clarification.
So may be suitable if you wanted someone to review what you've written for problems, but not making their own changes in the tone or content of the piece above and beyond this.
The "five Cs" summarize the copy editor's job: Make the copy clear,
correct, concise, complete, and consistent. Copy editors should make
it say what it means, and mean what it says.
Typically, copy editing involves correcting spelling, punctuation,
grammar, terminology, jargon, and semantics, and ensuring that the
text adheres to the publisher's style or an external style guide.
Copy editors are expected to ensure that the text flows, that it is
sensible, fair, and accurate, and that any legal problems have been
addressed. If a passage is unclear or an assertion seems questionable,
the copy editor may ask the writer to clarify it.