Thats part of it.

In the case of the 1st DCR it was several changes of orders, leading to a last minute change from a counter attack vs a bridgehead at Dinant to a suprise meeting engagement while refueling much later than intended. So add supply problems to that one.

The 2d DCR was caught scattered across fifty kilometers of countryside while moving from its reserve position near Rheims to a new assembly area in Belgium. The tanks companys had just uloaded from railcars and were to far apart to support each other, while the infantry and artillery battalions were still far south in France.

The 3rd DCR was frittered away in small attacks despite every advantage of artillery, infantry, and supply support.

The fourth DCR was hastily assembled and made a couple of unsupported attacks which scared the s...t out of the local German soldiers and maybe Hitler but accomplished little else.

The 1st DLM was sent off with a motor infantry divsion to secure the approaches to the critically important port of Antwerp and to establish a safe route to Holland. It arrived a few hours to late, gave the 9thPz Div a rough day, then was ordered back south to block the advance of Kliests armored group to the Channel. It fought Kleists right flank for a day or two then was ordered back to prepare for a new larger attack. Eventually it was simply worn away by the long road marches and three or four battles.

2d & 3rd DLM fought a three day delaying action (12 13 14 May) between Hannaut and Enghlize to cover the establisment of the French 1st Army in the Gembloux region. On completing that mission they werre withdrawn into 1st Army reserve and dispresed into several battle groups. After the 1st Army withdrew toward Lille they fought another brief rearguard action, made two counter attacks (Arras ect...) on the flank of Kliests 'panzer corridor' and spent their last strength as reaguard of the retreat to the Channel.

The five mechanized cavalry divsions (DLC) were sent into the Ardennes to support the Belgians in delaying the German advance there. The Belgians retreated beefore the French arrived and four of the DLC were suprised by seven German armored divsions with over 2000 tanks, vs 300 light models of the DLC. In less than three days the last of them were chased back across the Meuse with heavy losses. Subsequently they were used as reinforcements for other larger formations, or as screens and blocks where there was nothing else.

In late may the French completely reorganized the DLC and two remaining DCR into a half dozen ad hoc armored divsions with whatever tanks and motorized battalions were available. Three of these were grouped together and counter atacked a German armored corps in the June offensive. After initial sucess the group was attritioned away by superior numbers of tanks, artillery, and air. The other armored divsions met similar fates as they made several counter attacks vs the new German advance into central France.

As it was between the 15th & 17th of May there was one slight chance to use the 2d & 3rd DLM in a decisive way. Instead of dispersing them into reserve positions behind the 1st Army north of Namur, they could have been ordered to attack south into the flank of Kliests breakthrough south west of Namur. There they would have cut behind the German armored divsions, rather than hitting them directlly as at Arras. I say again this is a very slight chance as the French Generals in Belgium did not understand yet what was going on to their south, and few to none of them would or could have acted with the necessaary speed. Still a pair of armored divsions followed by a couple of motorinfantry div into the rear of Kliests panzer group would be trouble.