وَمِنْ أَتْبَاعِ الْإِمَامِ أَبِي مَنْصُورٍ الْمَاتُرِيدِيِّ فِي الْأُصُولِ
And in theological foundations he followed the scholarly approach of Imam Abū Manṣūr al-Māturīdī.
Here uṣūl concerns foundational questions of belief. The association locates al-Nasafī's theological argument within the Maturidi tradition. Hanafi describes a jurisprudential connection, while Maturidi here describes a theological methodology; the two affiliations are not contradictory.
Naming a tradition is a historical and intellectual identification. The reasoning behind a particular position, and its differences from other approaches, must still be examined in the discussion where they arise.
Contrast: A question about the principles governing divine attributes is theological; deriving a specific ruling for prayer belongs to applied jurisprudence. Both need evidence, but they differ in kind.