What were the advantages of the French and British troops at the beginning of the war?

At the beginning of the war, the situation was in favor of the British, since they were able to inflict several major defeats (Battle of Slacy, Battle of Crecy, etc.) to the French. In fact, the French army had only drawbacks: slow and weakly maneuverable knightly cavalry, lack of archers, lack of interaction between troops, weak commanders. The British, on the other hand, were well organized and had a large number of archers, who inflicted significant damage on the weakly maneuverable French cavalry.