Wildfire severity and frequency continue to increase worldwide, making effective aerial wildfire suppression a critical component of wildfire response. The COLOSSUS (Collaborative SoS) X-Challenge project established a system-of-systems (SoS) framework to design and evaluate next-generation firefighting capabilities and operational concepts. Building on this framework, this paper presents a simulation environment that jointly evaluates conventional fixed-wing and electric vertical takeoff and landing (eVTOL) firefighting aircraft concepts by integrating aircraft design, fleet-level coordination, and mission-level tactics into the unified SoS assessment, enabling performance-driven design exploration. The framework was expanded with new tactics, including a ridge-based drop method, and a flanking selection algorithm that leverages road networks to establish anchor points and construct fire lines. Simulations across three representative wildfire locations (Salamis, Pyrenees, and Palisades) demonstrate that combining purpose-built aircraft with adaptive tactics can significantly improve mission effectiveness.