1) Illusions shouldn't be able to attack. It will still LOOK like it attacked, but no damage it inflicted. Any decently-intelligent enemy will know that some of the creatures are illusions, though it will be hard to pinpoint an exact one.
2) That said, it should have 1 attack instead of 0, since the ability isn't particularly powerful.
3) Oh yeah, and I almost forgot the famous argument..."This + Fractal = OP!"