Why did the appearance of the Berger Picard vary significantly until the 20th century?

Answer

They were valued purely for function, not conformation

Because they were valued purely for their working utility, minor variations in physical traits like ear set or tail carriage were considered secondary to performance until standardization efforts began.

Why did the appearance of the Berger Picard vary significantly until the 20th century?
raceOriginDogbreedingBerger Picard