Does the Goblin Hexer's Vexing Cloud grant concealment and an additional -2 to hit?

Question

The Goblin Hexer's Vexing Cloud is a standard action with a zone:

Area burst 3 within 10; automatic hit; all enemies within the zone take a -2 penalty to attack rolls. The zone grants concealment to the goblin hexer and its allies. The goblin hexer can sustain the zone as a minor action, moving it up to 5 squares.

If the Hexer centers the blast on himself and it grants him concealment, do melee attackers then take an additional -2 to hit because of the effects of the cloud.

To break this down, assuming that concealment grants the Hexer +2 bonus to defense, and the cloud make its attacker take a -2 to attack.

Does that mean that the attack modifier from the cloud is -4? (-2 concealment + -2 cloud effect)

Answer 1

Yes

Any enemies within the zone will have an effective -4 to attack rolls. Enemies outside the zone only take a -2 from the concealment.