If a coon could only get their hand in there, there wouldn't be. Something could have also been outside the coop and caused them to panic. It's hard to say but I'm not sure both would die in such a strange way without an exterior cause. if you want to get one more chicken you can, but they'll be...
It's clearly not a disease or a sanitation issue, nothing that happened has anything to do with what you said, but I'm sure op appreciates your warm wishes.
That's why I'm still waiting for pictures of the coop, I'm not sure. In my experience, chickens typically don't care if they've been raised together or not, feathers will fly if they decide they hate each other. But there's no blood...I think something lifted the coop and went after what they...
They'll be fine with two hens. I'm perplexed by the fact that your cockerels were plucked, they could have been molting and killed each other. Can we see pictures of your set up? Sorry for your losses