N-ary tree protocols are used for access control on shared channels to resolve collisions among channel users. For exercising a single collision resolution engine (CRE), the throughput and latency of such protocols have been comprehensively studied. This study investigates the same protocols with multiple interleaved CREs in slotted networks. Power, defined as the ratio of throughput over latency, is measured as the criteria to launch or terminate CREs. Analysis results indicate that the appropriate number of CREs to trigger depends on the traffic load and the collision resolution protocol. As the load grows to 0.25, 0.35, 0.5, and 0.8, the optimal number of interleaved CREs becomes 2, 3, 5, and 8, respectively. Moreover, the power of n-ary tree protocol with n determined dynamically outperforms the 3-ary tree protocol by 13%.