Well, in that case, having him move forward off of the lead rope will be your first goal. Then backward, then yield front back and sides.
The horse you are leading is the horse you'll be riding, so if that horse is being dominant, heavy, sticky or resistant on the leadline, you might not want to even bother saddling up.
Work on having him responsive and respectful on the ground . And work in some things that are 'messy", like noisy things or other things that will disrupt him. I mean, folks often think the horse is doing so well on the lead rope, but only because he's in a perfect environment and as soon as there is something strange, the horse falls apart. Make him fall apart a few times. Or rather give him the chance to fall apart if he's going to do it anyway.