Yeah, swords are common phallic imagery, but not automatic. Bleach and YuYu Hakusho, for example, definitely use weapons as phallic imagery,and then, say, Utena does it for different reasons, but Claymore has never struck me as doing that.

And if we do look at big swords in Claymore as phallic imagery, then men who can use them quickly turn into insane monsters, while women who can use them can be fine for decades.