Recruiting at a service academy is extremely difficult. Not only do the candidates have to be able to keep up academically with a full cadet AND athletics workload, they have to be able to secure an appointment from their congressman/senator to even be considered. It's a very difficult process and it takes identifying and helping along early the exact right candidates in order to get them on board. Often, a recruit is placed in the NAPS/USMAPS/USAFAPS system for a year to get their academics in line. This means they have a year where they are "redshirted" but not practicing with the team. IIRC, they have "JV" teams there for the purpose of the Academy football team pipeline.
All this to say, for the last couple of years Navy has generally struggled in two related areas: QB and OL. For the 3O, QB is even more critical than in a normal offense, and Navy's QB has not been enough of a threat to keep defenses honest. OL is where academies struggle the most, as an OL body at any normal school would disqualify most cadets from military service. It's a major reason why the 3O is the offense of choice at academies. The Navy OL has struggled, and the results are there to see.
Can Coach N fix this? Sure, but at an academy, it's rarely a quick fix. They can't process out SAs as easily as other schools, and are generally stuck with their recruits for the duration.
Just my perspective as a former Academy Cadet.