I also took durability and recovery into account. Nothing is invincible, and the death star is nowhere near as close. Also, the forerunner weapon Composer bypasses every shield (to my knowledge), making your ray shield useless. Either way, it is a disintagratory ray, so it would wear the shield away until a pop, in which it would bypass the hull, assuming the shield does stop it. Even then, prometheans could teleport inside, in which the shit aim of stormtroopers combined with weaker weapons would kill.