I don't think that they had a crystal ball to see the future. There
was
no
reason to expect the fast fall of France and BEF.

Except for looking at what had happened in Spain a few years earlier.

Ah, the blitzkrieg of Spain is it?

No, the use of airpower and other tactics. Spain was a warmup for
German techniques a few years later.

Read up on the Spanish Civil War.

The Spanish civil war lasted years 1936, 1937, 1938, 1939. New equipment and
tactics were tested, but it was a long war. I wouldn't say that that Spanish
civil war was a direct indication that France and British troops would be so
quickly overrun.

So how about that navy question, what European nations could have used a
larger navy?