Noa and Asuma Work Because Their Strengths Do Not Overlap
Noa is the instinctive pilot. Asuma is the person outside the cockpit who sees software, hardware, corporate motives and the pieces of a case Noa cannot see from inside Alphonse.
The partnership gets interesting whenever the show removes one of them. Their argument before the Phantom rematch leaves Noa entering a dangerous operation without the voice she expects beside her. At the Labor Show, Asuma borrowing her movement disc creates a completely different vulnerability. During the damaged-machine Griffon fight, his guidance matters because Noa is working with failing sensors and incomplete information.
Then episode 47 makes the relationship wonderfully mundane again: Noa goes home to Hokkaido, and Asuma follows because somebody has to get her back.
Why it matters
Patlabor never turns 'best pilot' into 'person who can do every job.' Noa and Asuma work because their competence overlaps just enough to argue and not enough to replace one another.
Debut: Ep 020 - Movement in the Dark
Kanuka and Kumagami Change Division 2 Without Replacing It
Kanuka arrives looking like Division 2 has accidentally hired somebody from a much more competent television show. She shoots better, commands harder and initially makes Noa look undisciplined.
Then episode 14 happens. Noa disobeys her in the field, the two make each other furious, and Goto's solution is basically to get the whole unit drunk together. By the time Kanuka leaves in episodes 23-24, her absence feels like a genuine change in the workplace rather than the end of a guest appearance.
Kumagami enters with an equally intimidating resume but a completely different personality. Episode 27 immediately gives the hyper-competent newcomer an almost ridiculous weakness to ghosts, and the Griffon investigation later gives her a personal history with Utsumi that belongs to her alone.
Why it matters
Kumagami is not 'new Kanuka.' Patlabor lets Division 2 change shape without pretending personnel are interchangeable.
Debut: Ep 002 - Kanuka Has Come