The overlap check belongs before you publish.
Cannibalization is not a content-quality problem. It is four good posts targeting one intent, splitting the signal, none of them winning, and it is invisible from inside the editor unless something is watching the whole corpus.
What the editor does while you write
Live GEO checklist
The same answer-engine checks that run in the audit, applied to the draft in front of you: is the claim extractable, does the heading match a question someone asks, is there attribution metadata for an engine to credit. Fixing these while writing costs nothing; fixing them across two hundred published posts is a project.
Live E-E-A-T checklist
Whether the piece has a named author, a date, sourced claims, and the marks of someone who actually knows the subject. These are mostly Human-capability checks: the engine will tell you a claim is unsourced and will not invent a source for it.
Originality against your own corpus
Not plagiarism detection against the web. A similarity score against everything you have already published, because the thing most likely to outrank your new post is your old one.
An assistant that drafts, rewrites and retitles in place
Working on the document rather than in a chat window beside it. Its suggestions carry the same classification as everything else: a retitle is Assist, and a claim about your product is Human.
The calendar
The content pipeline as a month view: scheduled, generating, draft, published. It exists mostly so that overlap is visible before two people commission the same piece, which is where a meaningful share of cannibalization originates.
What this is not
It is not a volume machine. There are tools in this category whose pitch is publishing at a rate no human reviews, and the predictable result is a corpus competing with itself: the exact failure this editor is built to catch. Writing more is not the goal; writing things that do not cancel each other out is.
The overlap check is also advisory. It flags that two pieces target one intent; deciding which one should exist is a judgement about your business, and the engine does not make it.