An aftertreatment system comprises a first SCR system, a second SCR system positioned downstream of the SCR system and a reductant storage tank. At least one reductant insertion assembly is fluidly coupled to the reductant storage tank. The at least one reductant insertion assembly is also fluidly coupled to the first SCR system and the SCR system. A controller is communicatively coupled to the reductant insertion assembly. The controller is configured to instruct the reductant insertion assembly to asynchronously insert the reductant into the first SCR system and the second SCR system.