I probably would keep the expensive breeds confined, and let the common ones be the expendable characters....
I just got some brown leghorns because supposedly they are good at evading predators.  My neighbor has dozens of them wandering all over the place, crossing the road, etc.  Last year,  I lost a couple of mine that were heavy dual purpose breeds, so I researched what my neighbor has and found there are breeds that are considered better at avoiding predation. The brown leghorn is very common and inexpensive.   I'll see what happens.   I believe that at least they will have a better chance at survival than my Buff Orpington did.  
I got some bantams that will probably not be allowed freedom when they grow up.