The present invention is directed towards systems and methods for load balancing by a multi-core device intermediary between clients and services. The device may establish sub-slots in each slot of the device's packet engines. The number of sub-slots may correspond to the packet engine count. Each slot may track a different number of active connections allocated to a service. The device may assign a first and second service to each packet engine in a first slot corresponding to no active connections. These services may be assigned to different sub-slots in adjacent packet engines. The device may update, responsive to allocation of a first active connection to the first service, the first service from a sub-slot in the first slot of a first packet engine, to a corresponding sub-slot in a second slot. The second slot may correspond to one active connection allocated to the first service.