Why 1945 Free French forces would need concentration to stop Germany in 1940

Could the entire Free French military of 1945 stop the German invasion if transported back to 1940?

Only if it appeared concentrated on the threatened front; in its historical worldwide positions, the force would be too dispersed.

Extra troops and equipment matter only if they arrive where the German offensive can be stopped. The 1945 Free French forces were distributed across the world, so teleporting them back in their historical locations would leave them too dispersed to change the campaign immediately. Concentrating the same force on the threatened front could produce a much stronger defensive effect.