Yeah I have been worried about that too... Adding Modern has been an experiment and if they turn out "watered down" then I will get rid of them. The Modern hen that I use is pretty tough, and her full brother died in a natural scrap against of my wild types. So it lends me to believe they are game. So far I don't see any issues and I'm happy with results. the crosses have dark legs and are solid white. I just wish they were taller (longer legged) like the Modern.