The General's Five Death Flags

Yeonu Ahn's character is NOT supposed to be like this. From what she read in her past life, Yeonu is just supposed to be the cheeky, adorable, and innocent younger sister of the male protagonist in the magic/fantasy novel, "The General's Five Blossoms"! So then why is she (currently living as that same Yeonu) stuck in the Royal Army and pretending to be a man, in the place where her brother was originally supposed to be gathering the five lovely mistresses for his harem?!

...Fine. When life gives you lemons, right? Just as Yeonu decides to accept her fate and reap the material benefits of working in the army so she can retire early without having to lift a finger later in life...

Who are these important men popping up from the novel that were only mentioned once? Why do they all end up flocking to her side like she's the real protagonist?! And what's this about sudden war tensions between nations?!?! Has the novel gone mad?????

Please...! You've got the wrong guy (girl)!