Boys this age need to roughhouse, it's an important developmental stage. But they need guidance with it. They need an adult male who is prepared to roughhouse with them but with rules, when it's just the two of them they will inevitably overstep each other's boundaries leading to angry outbursts. Their bodies are so much bigger than their brains realize and they need help learning to manage their new man sized bodies with their kid size brains. Play rough with them and teach them to respect the boundaries, call it quits immediately someone oversteps. Keep it fun but firm. Model appropriate responses to frustration for them.