Keyword clustering, and why the source matters more than the algorithm
Most keyword clustering tools are judged on their clustering method: SERP overlap, embeddings, n-gram similarity. That is the interesting engineering question and almost never the one that decides whether the output is useful.
The decisive question is what went into the cluster. Cluster a list of real ranked keywords and you get a plan. Cluster a list a model imagined and you get a beautifully organised plan for pages nobody is searching for. Because the structure looks identical either way, there is no point at which the mistake announces itself.
So the guarantee here is about provenance rather than cleverness: every keyword in every cluster came from a DataForSEO response, and every volume and difficulty figure is re-read from that response at display time.