Gameness is heritable, very strongly so and comes from hen side as well as cock side. Gameness is easy to dilute by outcrossing with a nongame breed. I incorporated games into one of my American Dominique projects resulting in an immediate reduction of gameness to level suitable for multiple rooster flock. They still scrap a little more than pure American Dominiques. Less aggressive rooster himself will be easier on stags. I am not convinced losses of original concern where not caused by stags themselves. In most instances where I had similar problems the stags would not scrap with old rooster directly, rather they fought amongst themselves and only in later stages would the cock (old rooster) get involved.Finding carcasses does not mean they died of hunger or thirst or that they were in bad shape. It’s quite possible a predator did away with them. Killing one and dragging it under a building to eat it sounds like it could be many things, raccoons and bobcats for example. Totally free range birds are not likely to be fat and heavy. They are likely to be trim and fit, in good physical shape. Game birds are built this way to start with.
Centrarchid, would bringing in a less-aggressive breed rooster help with the offspring that much? Wouldn’t the offspring inherit aggressiveness and gameness from the mother as well as the father?