Isn't it pretty stupid to gather that many shinobi together like that? If I remember correctly, it was earlier believed that Akatsuki wanted to use the tailed beasts to create a "nuclear bomb" ninjutsu. Who says that's changed? (Well, expect Madara, but who trusts him anyway.) Even without the power of the tailed beasts, someone like Pain could inflict major damage to that army if they're grouped together like that.

The whole Edo Tensei thing also bothers me - Do you need the bodies? Can you resurrect people consumed by Death? etc. - but I guess I'll just have to be patient and wait for episode 264.