Looking at two current tank classes we have to think how can a third tank fill the roster without overshadowing the current tank(s) in the game? Easily, by implementing an evasion/counter-attack tank such as the Samurai.

Kamae (構え?) is a Japanese term used in martial arts and traditional theater. It translates approximately to "posture". The Kanji of this word means "base".

Sword Oath like toggle ability for Samurai:
Jōdan-no-kamae the sword is raised above the head with the tip (kissaki) pointing back and the blade facing up, in readiness to strike.[1] It is the most aggressive stance of the five.