According to the book some military reasons are found:

Weygand´s combative style initially had a galvanizin geffect effect after the torpid and distant leadership of Gamelin.

Second, soldiers who had experienced German air attacks in early May had become partially inured to them. at least to the shrieking of the Stukas.

Third, the High Command had altered its tactics. Abandoning the orthodoxy of the continuous front, Weygand adopted the "chessboard" defence system made up of Hedgehogs, points of resistance centred on a natural obstacle like a wood or a village, and protected by all round by artillery. The gunners were now instructed to fire at tanks on sight, like a revolver, rather than, as French doctrine previously prescribed, being employed only for concentrated fire under centralized control. This gave greater flexibility to the defence.

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