Don't get me wrong, I was just analyzing raw stat gaps between the samurai. I'd take Shizuka over Chizuru almost any day (lower defense but higher HP makes healing incoming damage more difficult and the HP bars deceptive). Early rushes are generally handled by Archers/Witches + Soldiers, possibly a rogue if you're not sure you can kill quick enough and want to gamble (I believe Castle Retake has a Cypria-reliant strategy for underleveled players looking to rush to Dragon Hunting/Flame Dragon, as an example of this), Samurai are a mid-map anti-rush mob clearer class, and while Chizuru's cost is lower than other samurai, it isn't low enough to be viable for early rushes in most cases.