Sluys and English raids hollow out the French Channel fleet

The French need for hired Castilian power followed a sustained loss of shipping rather than a single isolated defeat. Sluys had wrecked the main fleet, and Edward III's later campaigning repeatedly struck concentrations of French vessels. France was reaching the point of lacking ordinary ships in the Channel, not merely purpose-built warships. That weakness reduced the immediate invasion danger to England, although wooden fleets could be rebuilt quickly enough that the advantage was temporary. De la Cerda offered larger vessels, experienced crews, and a proven commander, making the contract a practical answer to a depleted French naval system. Cumulative attrition had forced France to purchase maritime capability from outside its own fleet.