I never heard about "ensemble-base approach" however by quickly looking the definition in the wikipedia ("Ensemble methods use multiple learning algorithms to obtain better predictive performance than could be obtained from any of the constituent learning algorithms.[1][2][3] Unlike a statistical ensemble in statistical mechanics, which is usually infinite, a machine learning ensemble refers only to a concrete finite set of alternative models, but typically allows for much more flexible structure to exist among those alternatives.") I dare to say YES! Actually there are already some papers on DDoS attacks that uses ensemble-based approach. See bellow: