Cepero/Ayats look like the more structured pair for Riyadh: Cepero’s left-side control plus Ayats’ right-side stability should translate well in quicker indoor/desert conditions where first-strike padel matters. Del Castillo/Vilariño can disrupt with pace and aggressive transitions, but they’ll need a high conversion rate on break chances to offset likely longer defensive stretches. Slight edge to Cepero/Ayats in consistency and point construction, especially if they win the volley battles early.