The culling bridge= the antithesis of the rainbow bridge. So sad!
Apologies for the tactless joke... But it can also be a necessary kindness, so it’s very good that you’re considering it before you get there. Some places it is very hard to find a vet that will see poultry, so you many need to be able to do it yourself and it’s good to have a plan in place if it is needed.
My mixed flock also includes Silkies, and a couple bantam Polish coming in a few weeks. It's often claimed these are physically unable to live in harmony.
Quite honestly, most breeds are compatible. Just keep an eye on the situation.