For Flamenco, allow the connections to shape the itinerary: travel to Ceiba or an airport, reach Culebra, arrange the beach transfer and protect the return. Staying on Culebra changes the day from a sequence of connections into an island chapter. Tortuga adds a boat outing; do not assume a ferry ticket includes it.
For Buyé and El Combate, the practical advantage is grouping the trip within Cabo Rojo rather than crossing the island for several unrelated stops. Compare the beach day with time for food in Boquerón. Mar Chiquita belongs to a different North Coast plan; Playa Sucia belongs to the southern Cabo Rojo peninsula.