Two questions. In the first, a knowledge graph and agentic retrieval reach the same answer. In the second, only agentic can — and the reason why is exactly why we'd start with agentic retrieval and build the graph on what it teaches us.
Everything a graph can answer, agentic can answer too (Example 1) (except for specific niche cases, i.e. aggregation queries for analytics (not needed here)) — and agentic also reaches answers the graph structurally may not be able to (Example 2). In raw capability, it contains the graph. The graph still earns its place where its narrow strengths matter most — predictable low latency, deterministic paths, and high-frequency lookups that don't need fresh reasoning each time — which is exactly why it stays a module we build rather than a box we skip. We lead with the more capable approach, and bring in the knowledge graph when it leads to latency or other benefits that are needed.
We're not choosing agentic instead of the knowledge graph — concept mapping & linkages is a module we will build. The point is sequence: running agentic first is what tells us the right ontology to build the graph on, so the graph we eventually ship covers the Example-2 cases instead of missing them.
The goal Eric cares about — getting senior people's judgment out of their heads so it survives retirement — is exactly the case where a hand-built graph is most brittle and agentic retrieval works out of the box. The instinct that this "needs a knowledge graph" is backwards on this kind of data.
It doesn't live in tidy documents with clean filenames. It lives in conversation — senior people thinking out loud, explaining the why behind a call. The value is in the implicit judgment, not in keywords.
This is the example where the two genuinely diverge — and it cuts against the graph, not for it.