If he really wanted to avoid fighting, then why did he ever challenge the protagonist to a fight? Also, note that Grimsley says, "Man oh man... What is going on today? Challengers coming one right after another", just before you battle him, and Cheren defeated the E4 after you, so N must be the person Grimsley is referring to. If he bothered with the E4, then he should've bothered with the gym leaders. If he wanted to just steam roll through and ignore rules, he would've ignored everyone and just gone straight to Alder, but N believed he was meant to "capture the hearts" of people, so he had to do things "right" or would be seen as a fraud.