The Finch strain seems to be the smallest. I think some of the other strains have suffered from being inbred too closely. However, some of the other strains are also based on the Finch strain.
Finch Strain (base)
Horst Schmudde added Shamo and bred to type
Bayliss birds came from Schmudde
Brush birds came from Bayliss
Finch Strain (base)
Horst Schmudde added Shamo and bred to type
Bayliss birds came from Schmudde
Brush birds came from Bayliss