Castillón/Portillo bring a more aggressive, high-tempo profile, but against Sainz/Montes in a Major setting the match usually turns on patience and shot selection. In Italy conditions tend to reward compact defense-to-attack transitions and disciplined bandeja/víbora patterns, which suits the more structured pair. Slight edge to Sainz/Montes if they control the right-side tempo and avoid gifting break points early.