Your welcome, and you do have my apologies as well. They are handsome.
You mention that you have a breed that is supposed have a lot of the "game" bred out of them and now I think I see where you're coming from. Reading back over your initial post, as well as, glancing quickly at your posting history, I see what you mean and realize that I made a mistake. I was quite confused when you were disappointed that your "game birds" were fighting. Now I understand a bit more, I think.
You're wanting "non game" game birds. I'm going to go out on a limb here make the assumption you are referring to the Liege Fighters you have. So, if you are finding that one is too aggressive for your liking, then culling would be warranted. A funny thing is they taste like chicken, cull young and have a nice meal. Let the others grow out and see how they do. Colors are pretty, but it sounds like your main focus is on behavioral traits. I think we can agree, they are handsome birds, but if handsome doesn't meet your criteria, then cull and focus on the next 2-3 birds until you see what you are wanting.
Many folks keep a mix of breeds in a flock, quite a few here on BYC keep multiple roosters together, but I know of no one that keeps Game Gamefowl roosters together. It just doesn't pan out. Birds will kill one another, that's a fact.
Again. I will say it again - No, I personally know of no measures that would curb "Gameness" except for penning or culling.
And if the "kill it before it grows" remark it directed at me, then fair enough, but I would like to know why you think that?