Caldera/Goenaga look like the more stable “structure” pair: clearer roles, heavier first-ball pressure, and fewer tactical swings point-to-point. Osoro/Iglesias bring higher volatility and creativity—dangerous in Buenos Aires if they can speed up exchanges and turn defense into attack. Slight edge to Caldera/Goenaga in a tight match, with Osoro/Iglesias’ comeback chances hinging on rhythm and net dominance.