Ren Xiaosu did not want to have any dealings with the Zhou Consortium troops, nor did he want to get involved with the Pyro Company. After all, he had manipulated "Old Xu" into killing quite a few of the Pyro Company members in that incident at East Lake. In a sense, they would surely have quite a huge grudge.
So by the time the Zhou Consortium's emergency response force arrived, Ren Xiaosu had already left.
After three waves of attacks and probing, the Experimentals had completely retreated this time. As the saying went, "Three strikes and you're out!" Having failed to take Stronghold 74 with three straight attempts, there was no need for the Experimentals to continue wasting their efforts here. Instead, they should be going back to the drawing board to identify their next opportunity.