Heterogeneous A/B/C/D Pool Dispatch: Real Model Comparison Without an Eval Harness

You need to know whether model-X is worth deploying for your real workload. The benchmarks suggest yes, but benchmarks are static and your workload is not. The standard answer — build an eval harness — runs into two structural problems: harnesses are expensive to build well, and they tend to over-fit to the inputs you remembered to include in the corpus, missing the real production failure modes you discover only later.