I can understand why some people thought that later volumes have supposedly 'regressed' in terms of action and strategy, particularly where Chang ge is concerned. I once shared their feelings, but upon reading the series again I find that there’s little ground to back up this claim.
First, there can’t be wars and battles to be fought all the time. The first volume features this theme heavily, but war in itself is not the focus of Chang ge’s journey. It’s about finding herself and finding her allies. This series is elegant and deep, and definitely NOT only about bloodshed, betrayals and vengeance. Second, I want to clear up some possible misconceptions about Chang ge letting go of her vengeance and (so far) dropping her male guise. In what I’d call the second major arc of the story, Chang ge is brought to a peaceful temple, where she learns and reflects her 'Dao’ (path) and 'Shu’ (method). This is where Xia Da pays homage not only to the greatness of ancient Chinese war tactics, but also to its beautiful philosophy. After realising that her vengeance would bring her small personal satisfaction at the cost of her own people and country, Chang ge finally embraces a new goal and her inner desire for peace instead of chaos. It’s not that she forgets and forgives. In her talks with Ashina Sun she still clearly wants to kill Li Shimin, but not knowing how to do so without conflicting it with her new lifelong wish.
As for her disuse of her male guise lately, I like to think that Chang ge is learning more about her own gender identity, which she has been greatly confused about before. Also, her guise is only part of her 'Shu’, as she explained to Sun - they are all the real her. She becomes what is needed in the circumstances to advance her goals.
Okay, after clearing up that point, I’d like to profoundly express how much I admire Xia Da’s work and characters. Chang Ge should be a role model for young girls (and boys) not because she is perfect, but because of she teaches you. She is intelligent and strong, and I mean REALLY intelligent. I’ve read mangas under the tag of 'intelligent/clever female protagonist’ who in reality just falls into the 'shoujo perfect student' trope (good looks, top grades, athletic). Which is not a realistic (or original) portrayal at all. Many shounen manga, on the other hand, is guilty of the opposite. They often mistake a strong female character for just someone who fights as equally as a man. Think about it, how often do you find a female protagonist who is a leader? Who doesn’t need to be one of the best physical fighters in order to be important? ...That’s where Chang ge is awesome.
But Chang ge doesn’t make perfect decisions. She miscalculate, misjudges and pays the price for it. She couldn’t save many people. But through her hardships she grew as a character, always becoming more than the person she’d been from the beginning of her journey. That’s why I believe Chang ge makes a good role model. She isn’t born with perfect talents and the skills. She’s strong because she’s constantly perfecting and remaking herself.