They did to a degree. The
United Tribes of New Zealand was a very hands off union of Northern North Island Iwi, but it was the body by which negotiations for most of Nga Puhi took place and was a Protectorate of the British Empire . Unification of the North Island was unnecessary to have a Māori majority on Te Ika a Maui. Merely have the British respect and acknowledge Te Tiriti as the basis of government in the colony. Tribes would centralise and form a "Parliament" analogue that ran Māori affairs in the nation, likely to the tikanga of that particular iwi, while the Crown governed Settler populations and negotiated over land.
Māori would have maintained the communal ownership model that allowed them to largely outcompete early settlers economically, and sold goods to the growing settlements in Australia. It took the New Zealand wars to unseat Māori economic hegemony in the Settler colonies and then using Land Courts to divide and break up Māori iwi and hapu confiscations as well. Without the destruction of economic hegemony and an earlier respect for Māori sovereignty, you'd likely have a far more Māori North Island.
Key areas of development would have been the Northland region, Waikato-King Country, Bay of Plenty, Tairawhiti, and Taranaki. Likely run by local council of chieftains and largely autonomous. Travel by ship would be far more common as the impetus for road building was largely to make infrastructure to invade Māori tribes. So more disconnected local economies with a greater focus on rail and shipping. All would probably compete in British and local Pacific markets when technology allows for it. Far greater preservation of Māori culture and values, especially that of local iwi.