I have tried the kick the opp's opposite bicep method with poor results. Today Jay the Judo BB showed me a Judo method, which is very OMJJ Approved. All it requires is falling to your side. Even I can do that.
When you are in position with the arm trapped and about to lean back, the opp has a tight bear hug grip on their own arms. I f I fall back, they may just roll with me and get on top. The trick is to further close your bear hug on their arm and grab your Gi on the elbows. Then, fall sideways and arch your torso to extend their arm above their head. They cant hold their grip when it is extended above their head. With the grip broken, you then need to move back to perpendicular to the opps body and finish the arm bar.
I have not tried it in sparring, but it seems easy, requires little energy (i.e., fall sideways) and stops that problem with my arm bar. I am so slow that any opp can see me broadcasting the transition to arm bar a mile away. They then lock their grip and I am stuck hugging an arm that if I execute the arm bar they roll right with me and on top of me.
This video is similar, but how Jay taught it was to just lean to the side and not change the position to be nearly on top of opp. But, hey look, they are old too.