Well, I don't really consider this the best advice, but here it is anyway... You could shackle the rooster.
This will directly impede his ability to attack your husband and son, but also predators... However if a real predator decided to have a real go at the flock chances are all the rooster would achieve is be the first to die anyway. They're prey animals no matter how aggro they can be, they're not really equipped to take on a serious and hungry predator. And if it's an ongoing source of stress to have him aggressive, as it clearly is, shackling can help a lot. I've used it on a psychotic female turkey to stop her from killing another female turkey. It didn't change her mind about wanting that hen dead, but did enable her victim to live in peace. Sometimes, even once the shackle breaks, just feeling the 'cuffs' around the ankles is enough to keep them in a calmer state of mind.
To shackle them, you get a soft, thick, rounded shoelace and tie it around both ankles under the spurs, not so loose it can slip off but not so tight it cuts off circulation, leaving enough room for a normal length stride but not a running stride, making sure they are no-slip knots that will not tighten under duress.
It won't stop them mating normally (male or female), scratching themselves, digging, dustbathing, jumping up onto and down from perches and nestboxes.
What this does is interrupt, physically, his charge. The first few times he tries to leap at someone wearing shackles, he will fall flat on his chest a few times before he understands he cannot charge anyone anymore. At first he'll probably do some annoyed high-stepping and back-kicking as he tries to free himself and figures out how to work it, but they learn rapidly. It's simple even for them.
Possibly not your ideal treatment but it works in getting aggressive animals to cease attacking.
Best wishes.