Finishing the RNC

I ask this question primarily about no-gi. I have a hard time to finish the RNC on guys who are any good. this is the position I come to every time.

I get my opponents back, and have one or two hooks, or the body triangle. usually we are both face up(if we are face down I feel like I am in a strong position to attack). I have my arms gripped around his body, garcia style. Which is to say one over his shoulder and one under his arm pit, and then I lock my hands together. and every single damm time he reaches up with both hands and grabs my top arm. I have a very hard time to make progress in this situation.

anyone have any slick tricks or good ideas from here?

change your hands. let say you have your right arm around his neck, he defends by pulling down. cross face with your left hand then quickly reaply with the right.

works for me.

sometime that one works for me as well, but against good guys, he clamps down on the arm that is under his armpit, making it dificult to pull it out and switch