As I stated, I love the arm triangle. It's how heavyweight beginners get to it and finish it that I don't like. If he can use a clean, technical setup, then finish it correctly...sure. But that won't happen for a 300+ lb guy. What will happen is he will muscle the arm up, have the choke on the jaw, squeeze hard and lay all 300+ on people and everyone taps. Probably could even finish from the wrong side..lol! but! That's not good training...that's exploiting your size in class, which holds your progress back. Same thing with the knee on belly suggestion. He didn't sign up for jiujitsu to learn how much a 300lb guy hurts when he kneels on someone's chest... He wants to learn technique, he already knows how big and strong he is.. The knee on belly is an amazing position, but I don't think it's meant to be used by big guys on little guys just to smash... It's a high finesse position requiring lots of movement . Again, I apologize if I upset anyone.