At Manchester City he is in the hands of a great coach who will take him to add to his experience. Haaland should be able to take advantage of this to become the best player.
Even if he is handled a professional coach, it does not guarantee his performance will be as good as before. For example like Aubameyang, before he was a Borussia Dortmund star with various achievements but when he played in the EPL for arsenal, his performance was still beyond the expectations of fans. In fact it took five seasons to record contribution of 68 goals
I'm more concerned with Haland's adaptation, can he adapt to a new club and maintain his form?