I’m a bit confused. You have 5 roosters, and you want more to protect your flock that is penned? I feel like you’re asking for trouble in trying to add more. Roosters need a lot of room to be able to get along. Fights are likely to happen when a subordinate rooster can’t get away from a dominant one. The dominant one can see that as a challenge, and the fighting begins.
Electric wire around the perimeter of your fence will not kill your birds. I have mine about 6” off the ground around my runs. It keeps nosy animals from snuffling around or digging under the fence. What kind of wire do you have covering your run? I don’t know that a hawk would tear through it to get to your chickens. If it’s chicken wire, I’d be more concerned about raccoons, mink, or opossums getting through it, and most roosters won’t be able to stand up to them anyway.