Haven't watch River Where The Moon Rises but it was one of a stage play in Jeongnyeon so basically a princess general. Hmm... Maybe lady general Mulan. I watched 2009 version movie.
Scarlet Heart Ryeo was a remake of Scarlet Heart, but I haven't watch it, doesn't seems like it has a lot of action though.
I think Romance of The Three Kingdoms has the most adaptation, so maybe you could try Three Kingdoms. It has a lot of action and a few romance.
For more romance but less action, there's Story of Yanxi Palace (about the third empress of Qianlong emperor). If compared to K-drama maybe it's like Dong Yi.
For some balance, hmm... maybe The King's Woman. I skipped it avoiding bad ending but FL was heroic and there's a lot of romance. It's about Qin Shi Huang who kinda made the silk road. FL was a fictional character though just like IU's character.
