I still say that calling Piper a Mary Sue is misunderstanding the intent of the books she's in. A Mary Sue is a guest character that steals the spotlight from the heroes. But Piper wasn't the guest character in this novel -- she was the lead character, just as Calhoun is the lead of New Frontier
, Reyes is the lead of Vanguard
, Rugal is the lead of The Never Ending Sacrifice
, etc. Dreadnought!
was the first attempt to do the sort of thing that's since become commonplace, to explore the Trek universe from the perspective of a different set of characters than the TV leads. In this case, it was an approach much like "Lower Decks" on TNG, or like the Young Justice
TV series vis-a-vis the Justice League -- showing us a story about a familiar group of characters from the perspective of their subordinates or juniors. The intent was to show us what life on the Enterprise
would be like for its junior officers, to show us how they would experience one of the adventures that Kirk, Spock, and McCoy were taking the lead on, how they would perceive and try to learn from these great heroes.
So really, if anyone is a Mary Sue in Dreadnought
, it's Kirk. He's the guest star who's better at everything than the central characters, whose actions guide the story, and whom the central character greatly admires. That's pretty much the textbook definition of a Mary Sue.