Originally Posted by
schismatic
Play normally but pay attention to your assist options. There's a few lvl 40+ nobunga's (img attached) with a 2ap row attack that wrecks the cavalry. Once you see one available try the boss again.
I only had castle lvl 5 or 6 and lvl 2-3 research before you unlock the 3rd tech for each class (hording ore for castle upgrades). I 3 starred with the nobunga assist, lvl 34 kenshin, lvl 30 ranmaru, lvl 30 yoshihiro, and lvl 30 musashi. All that really mattered were the nobunga and ranmaru for type advantage.