What French sources reveal about the Battle of Sluys

Is the Battle of Sluys mainly an embellished English victory story built from incomplete sources?

No; substantial French and Low Countries evidence confirms the defeat and often criticizes French command more harshly than English accounts do.

French and Low Countries evidence means the surviving account reaches well beyond an English embellishment. Jean Froissart is particularly critical of the French commanders, who had the larger and more experienced force and therefore expected to win. Their plan depended on the English attacking in the anticipated way, but storms changed the positioning and English maneuver exploited the resulting geometry. The victory later became mythologized on both sides, yet the hostile-source evidence still supports the scale of the French defeat.