The model is a component, not the product
The useful comparison is not which model is smarter. Frontier labs build general intelligence, and they are very good at it. The question for legal work is what surrounds that intelligence before an answer reaches a client.
ChatGPT and Claude give you a model. HAQQ gives you the legal system built around one: jurisdiction, sources, your firm's own knowledge, permissions, citations and an audit trail. The model does the generation. Almost everything that makes the output usable in a matter happens before and after that step.