Just to point out, a few of the MANY reasons why France lost to Germany were:
1 - tanks deployed in pairs or trios to support infantry. Typical scenario is, 2-3 French tanks encounter 30+ German tanks. French tanks have better guns, better armor, and a small turret with only Commander/Gunner/Loader or Commander/Gunner and seperate Loader. French tank commander spots German counterparts; makes a choice between waving signal flags to other tank(s), commanding own tank to seek a better position, or manning gun of own tank (possibly with assistance of seperate loader). By the time he gets in position to fire, German tanks (with seperate Commander, Loader, and Gunner) have already taken first shot. If not damaged or knocked out by the 30+ incoming rounds, the 2-3 French tanks shoot, with low probability of a hit on initial "ranging shot". German tanks reload and shoot, this time with acquired targets, and likely incapacitate one or more French tanks. At best, the French take out 1 German tank in every 2-3 encounters, while losing all 2-3 tanks every time. Not good if you happen to be French.
2 - French leaders took stock of the situation and the German advance through the Low Countries, and didn't know how to handle it. They delayed, then overcommitted, and eventually realized their mistake. Again, not knowing what to do about it, they did NOTHING. When you have NO ORDERS from your superiors in the face of an invasion, what CAN you do?
3 - French AT guns were mostly 25mm. 'Nuff said.
4 - Air power was decisively in Germany's favor. Anything that moved was subject to spotting and attack.
5 - The Maginot Line was mostly designed to face a WWI style attack, and many of the prepared gun positions were incapable of holding AT guns over 37mm, if even that. The Germans launched a number of "feint" attacks on the Maginot Line, both to divert attention from the main attack in the north, and to prevent the French from pulling much of the garrison to support the more critical situation. Much to the surprise of both sides, at least one of the weak "probes" actually managed to breach the line, but the breakthrough was only minimally exploited because there was no force dedicated to do so.
Despite all of that, the individual French units often put up a fierce fight, and German units struggled or were stopped in a number of places, but the overall strategic development went entirely in Germany's favor because "nobody was minding the store" at the upper levels of French command. One of the highest ranking officers (I forget the name) locked himself in his room for several days, rather than face the seriousness of the situation, leaving his subordinates without any means of coordination between units. Other units boarded trains, bound for the front, then received other orders to go elsewhere. By the time they got organized and got to where they needed to be, the fighting was already over. The German forces worked with an overall strategic plan, constantly updated and modified according to events. Too much of the French army acted independently with no cooperation between units, if it acted at all, because there was no plan for such an event, and nobody was willing or able to make one.
