Arturia has repeatedly been stated, and never [i]contradicted[/i], as the strongest Saber all around. On top of that actually blocking her attacks flat-out breaks non-NP weapons and even if you're strong enough to hold it off starts breaking the scenery around you. This is entirely without releasing Invisible Air in the slightest.

I like Julie d'Aubigny, but there's no way that her duelling ability is going to even remotely compensate for the straight power gulf for people who can [i]happily[/i] fight dragons. They're skilled [i]and[/i] have way more brute force.