The Battle of Britain Five Months That Changed History, May—October 1940 by James Holland (z-lib.org).epub

Poor French logistics were symptomatic of a system that was unwieldy
in every way. The chain of command was also top-heavy and convoluted,
with Gamelin as Commander-in-Chief, and then Général Georges as C-in-C
North-East Front, then three Army Groups under him, and within Billotte’s
First Army Group no fewer than five armies, of which the BEF, with half a
million men, was one. Furthermore, the French commanders were old. All
were in their sixties and command veterans of the First World War.
Commanding armies is an exhausting job at the best of times, but much
more so during battle, when there are few opportunities for sleep; mental
and psychological demands are intense. Army commanders need to be able
to grasp information and intelligence quickly and then act decisively,
something that is better suited to a man in his forties or fifties. Interestingly,
nearly all the German commanders were of this age: Guderian was 51, von
Kleist 58, Halder 55, Reinhardt 53, Rommel 48. Only von Rundstedt, at 64,
was of a comparable age to the senior French commanders.
The entire French approach was defensive and negative – and a
negative mindset takes hold in many counter-productive ways. The huge
cost of the Maginot Line and the appeasement and non-aggression line of
the French Government and political left also played an enormous part in
formulating policy, but this endemic defensive attitude – this rigidity to the
methodical battle plan – had ensured that there could be no French march
into Germany when Hitler reoccupied the Rhineland in 1936, nor again
when Germany invaded Poland in 1939. Had the French done so on either
occasion, the Second World War would almost certainly have never taken
place.
France’s unwillingness to step out from behind her defensive system
had also unwittingly proved to keen-eyed observers like Heinz Guderian
that France was not offensively minded and that her commanders were
overly cautious. It suggested they hoped to avoid a serious clash of arms,
which was absolutely the case.
No matter how obvious it might have seemed to the conservative
Gamelin that the German main attack must come through the Low
Countries, the failure to prepare for other eventualities was seriously
negligent. Nowhere was this carelessness more manifest than at Sedan.
The town effectively formed the hinge between the top of the Maginot
Line, which ended twelve miles to the east at La Ferté, and the mobile
north-east part of the line that had swung up into Belgium at the start of the