I agree with you about scanners (we banned them at Matasano), but not about the ceiling for agents. Having written agent loops for somewhat similar "surface and contextualize hypotheses from large volumes of telemetry" problems, and, of course, having delivered hundreds of application pentests: I think 80-90% of all the findings in a web pentest report, and functionally all of the findings in a netpen report, are within 12-18 months reach of agent developers.