Multi-robot systems can perform task-related collaborative behaviors while maintaining connectivity within the system. However, some robots may fail to execute tasks or converge relatively slowly due to connectivity constraints. We consider the case that some robots may not have tasks assigned at a certain time frame, and they may help the task robots to achieve their goals by forming a connectivity graph with flexible topology. Therefore, we introduce a topology correction controller to provide flexibility for the task robots to perform task behaviors by modifying the topology of the connectivity graph for a faster convergence rate. We propose a distributed approach of blending weighted rendezvous and weighted flocking to form the correction controller. We prove that this scheme can guarantee a faster convergence rate and provide flexible connectivity graph topology. We then present our result of a system of up to thirty robots in various cluttered environments and show that our approach of behavior combination is robust and scalable.