Immediately after a major disaster large volumes of solicited and unsolicited relief items start to flow into the disaster affected region. This phenomenon is known as material convergence. The sheer volume of incoming materials, coupled with limited resources, make sorting and distribution of relief items a difficult task. The challenge is exacerbated when a large portion of the unsolicited donations are low-priority or inappropriate items, diverting volunteer, space, and transportation capacity from more critical items. This paper investigates volunteer allocation decisions under material convergence and varying levels of high-priority donations. First, we interview disaster response practitioners to understand challenges with resource allocation decisions. Then, we model the donation arrival and sorting process for both solicited and unsolicited donations as transient multi-server queues. Using this model, we quantify the level of material convergence and evaluate the impact of resource allocation decisions on relief item output. We provide insights that can help address the problems of resource allocation under material convergence, that are critical to satisfy needs of disaster victims.