The reason I believe in Guarnerius players and Stradivarius players as distinct is this.
The Guarnerius of the best model is even still more powerful.
Paganini's favorite was a Guarnerius del Jes, though he had no less than seven instruments of the greatest Cremona masters.
The efforts of Stradivarius and Guarnerius contributed in a marked degree to assist Tartini in creating a new era for the violin.
The name of "Guarnerius" is probably known to every possessor of a Violin throughout the world.