I've been searching for a quantitative research on the matter(Warner-Bratzler shear force test) as opposed to subjective tests, but I can't seem to find one. Perhaps the Europeans have done this and it's a matter of more research from my end.
Both are known to carry the sex linked recessive dwarf gene(dw)
The Sasso(Hendrix) SA51a dwarf hen(3 pounds live weight at pounds 20 weeks of age)
https://africa.sasso-poultry.com/en/sasso-products/females/sa51a/
These dwarf/Bantam hens are the reason of the "Slow" to mature colored broilers...
I have a few Sasso colored Broilers(the use the same line of dwarf hens crossed with different type of males/sires to produce slower growing broilers for different markets) I am also saving a CornisX pullet to cross it with a Isa Brown Rooster.