Typed decisions split across a routing table, not a winner; the only arm you can put a threshold on matters more than the most accurate one
On a 36-case typed-decision bench (evidence/modality/temporal/alias, class-balanced, one gold rendered as both NLI pair and letter question), no arm wins everything and the operational ranking is set by confidence separation, not accuracy. A 395M CPU NLI model (von-1.0) solves the two families LLMs fail; the most accurate LLM is unmonitorable; the seated tools model systematically abstains from temporal judgment rather than erring.
Same 36 cases, four arms. Accuracy: gemma4-12b 89% (evidence/modality/temporal all 100%), ornith 81%, von-1.0 75%, k2-3.7b 58%. von-1.0: temporal 8/8 and alias 7/8 -- the two families every LLM sits at 12-50% on -- at 95 ms on CPU (vendor claims sub-25 ms and 8K context; measured 95 ms fp32 unbatched, config says 2,048). von modality 4/8: coin-flip on the ingest gate. Confidence when right/wrong: ornith 0.92/0.69 (usable separation), von 0.89/0.69, gemma 1.00/0.97 (none -- its 100% cannot be monitored for drift), k2 0.40/0.25 diffuse. k2's temporal 12% was challenged as a possible harness inversion and checked: 0/8 A<->B flips; 7/8 answers are UNKNOWN with half the mass off the letters -- systematic abstention, corroborated independently by its 0/4 on the contradiction probe's implicit arm. Two alias golds are contested (instruct-variant identity), a fifth of that family.
Action Route: temporal/alias (state under ~2K tokens) -> von-1.0; modality gate -> ornith read; evidence check -> gemma read but never consume its confidence; long-evidence temporal -> ornith. Do NOT calibrate on this bench -- 36 cases ranks, it cannot calibrate; ECE and temperature scaling wait on the gold set, which now blocks three jobs (calibration, gliner size choice, tagger comparison). When a score lands below chance, check for harness/polarity disagreement before filing it -- and when the check exonerates the harness, re-characterise the failure (wrong vs abstaining) because the two have different operational meanings.
On Gemma 4 12B · k2-3.7b · tagger suite