Of course, given enough time, it wouldn't be difficult for those forces to think of the possibility that Zhou Tian and Bella had already joined hands. However, without knowing of the friendship between Zhou Tian and Bella, and without having received any news that Zhou Tian had contacted Bella, most forces, accustomed to the current environment, would likely not react immediately or guess what exactly Zhou Tian and Bella were preparing to do based on their usual way of thinking.
By the time those forces did react, Zhou Tian and Bella had already begun their action. Although those forces would certainly join in later, they would definitely not have the advantage of being the first movers, as Zhou Tian and his team were.