Re: Leading your uke?
Yes, static exercises are excellent to discover where the weaknesses of uke are. Usually with dynamic execution you can cheat and hide your errors, static training displaying it very clearly. Very strong static attack allows you to adjust your posture, check for constant flexibility of the muscles, learn how to redirect attacker’s power, maintain correct distance and angles of your attack. You have to look where there is no resistance and enter there immediately. Of course, in the beginning, uke must be mature enough to not to change his attack by adjusting to your technique, to help you, otherwise you will learn not much. However progressively, once you become more comfortable, he should increase difficulty of his attack, by neutralizing your attempts to execute a technique. Next level can be two uke are attacking your arm with morotedori attack …etc…
You may see the video from Yoshinkan, also Saito sensei, and Kanetsuka sensei for some technical details how to approach such training if you can’t get help from your instructor.
Personally I’m including a lot of static exercises in my daily training.