One good thing about having dozens of brains is the ability to think outside the box.
Klaus has that.
His brain is so big that before they attacked the zombies, he played the Battle 1,002 times and ran hundreds of thousands of scenarios based on what he knew about the zombies, the terrain around their habitat, and what he would do if he were in the Vampire King's place.
In the end, the only scenario he saw as plausible was sending part of his warriors to attack the defenseless Earth while the major human army was occupied.
Klaus knew that was likely to happen, so he made sure all loopholes were filled with the right people.
It didn't take much thinking to know that the only place the zombies would attack was Jose City, located several miles away from the Dead Zone.
It was the only place they could attack. Of course, there was the chance that if the zombies went westward, swimming or using a ship to sail the sea, they could attack most cities on the other side of the sea.
