In the year 1346, when famous Battle of Crecy was fought, Edward III was based west of Paris. From there the king would have needed about a week to pass an order to his lieutenant in Flanders or receive a report from him. Let us assume that, to exircise effective command over a distant subordiante, a commander-in-chief has to go through four stages. First, he has to send a message to that subordinate and ask him for a plan. Second, he must have that plan submitted to him. Third, he must transmit his orders back to the subordinate. Fourth, he must receive a confirmation that those orders have been understood and will be carried out. Still assuming the king is based in a region west of Paris and his subordinate in Flanders, the entire cycle will require a full month to go through. Of course it’s an ideal cycle and thing can rarely be completed in such precise form.
Other English armies operating in France at the time were even further away and even harder to reach. A considerable force was stationed in Gaskony, however, communicating with them took about twice as long as with the one in Flanders. As a result, for armies coming from different fronts to join hands was usually possible only when they were not opposed by a strong hostile army. As a matter of fact, we have reason to think thad Edward did intend to have three armies meet before fighting the battle. However, communication difficulties seem to have interfered and prevented the juncture.
So the dire situation in which he found himself in a defensive position between two woods and fought outnumbered was the result of the failure of operational art, to the extent that he understood it and tried to exircise it.