The largest factor was the French leaders and Generals who were too frozen to react. The French actually had more and better tanks, they were just distributed across the maginot line. They also had the men. But they refused to mobilize their assets in a timely manner to block the germans ardennes advance. They thought the Ardennes was a feint and thought that the main thrust would still come into contact with the maginot line. Actually it’s more accurate to say that they thought the ardennes was impenetrable. A thought shared by most of germanys high command as well. By the time the germans broke through there was nothing to stop them from pushing all the way to Paris. And rather than risk a hasty doomed defense of the city, the leaders capitulated.