Since Arms has lacked so much survivality in most of its existence, i am all in favor of Arms 2h and Shield. Basically a DPS version of Prot but with a 2h. Giving Arms a much needed Buff in defense plus abilities to Block attacks would make Arms a more melee combatant threat compared to its other Plate rivals.
And no, Defensive Stance doesnt solve this issue. It lacks alot of the much need utilities of a shield and also renders the Warrior useless since it nerfs thier damage and thats the only core the Warrior has outside of running.
Also a Shield fits the theme of being Tactical.