The PCs are a team running in the professional arena circuit. Like many other successful teams, the PCs are famous celebrities almost universally loved by commoners and nobles alike.
They lead a double life, however, as they’re actually agents working for their crown. The world-traveling lifestyle, with frequent and easy access to all walks of life, is the perfect cover.
Rivalries in the arena may turn into rivalries in espionage, or the PCs might discover some surprising new allies…