The great monks, being intelligent as they were, quickly grasp the implication behind Elder Yang's tactics.
Without a doubt, "guerrilla" tactics are an excellent strategy.
With Cao Chengxiang acting independently, and the four seventh stage combatants led by Su Yu acting collectively, it's tantamount to the Blue Star side deploying two eighth-stage beings to attack the Spring Eye.
In such a situation, if the Skurus want to delay their progress of capturing the Spring Eye, they will have to send out beings of the eighth stage or above, or about ten of the seventh stage to interfere.
However, the problem is once the eighth-stage powerhouses pass through the space cracks, these cracks would become shaky, shrunk, and extremely unstable, typically requiring about three hours to allow such powerful beings to go through again.