Model routing over model loyalty: splitting workloads across GPT-5.6, Sonnet 5 and Grok 4.5 in 2026

Model routing over model loyalty: splitting workloads across GPT-5.6, Sonnet 5 and Grok 4.5 in 2026 Summary. Three frontier models landed within ten days in mid-2026: Claude Sonnet 5 on 30 June, Grok