The reason the Divine Kings couldn't enter Zhou Tian's Treasure Space wasn't due to their lack of ability; it was because Zhou Tian retreated early enough that those Divine Kings couldn't find a target to exert force on. Without the Spatial Rule Cultivation of a Space God King, it was impossible for them to find the position of the Treasure Space without any clues.
In fact, if not for the Space God King having entered the Treasure Space once, even with his ability to directly find its position, it wouldn't have been easy.
And what even the Space God King might not accomplish, other Divine Kings with a Spatial Cultivation less than that of the Space God King would stand no chance against Zhou Tian without some other tactics.
Being unable to accomplish that doesn't mean those Divine Kings were weak; they simply couldn't find a target to direct their efforts at. That was why at the time, those Divine Kings posed no threat to Zhou Tian.
