Is there any way to make the rescue plan make sense?
Can’t think of any.
It is a mess.
But I don’t think there is anything you can do, without reshooting this part of movie.
I believe it is certainly possible to improve it. It requires a little bit of imagination (as some cases are with Star Wars), but the most important step, as I’ve already suggested before, is to remove that scene of Leia/Boushh bringing in Chewie. Scenes like this, which deviate too long from the plot, unnecessarily drag on the overall sequence with Jabba anyway. So with nostalgia aside, it would work better to have both Lando and Leia already in the palace in their disguises, who have infiltrated and are learning what they can about Jabba and his palace; they would theoretically be reporting back to Luke when possible. It should then be inferred that Chewie gets captured some other (not important enough to know how) way. It’s when Luke hears about or senses Chewie’s capture (and likely sensed Leia’s too) that he sends the expendable droids (even if he still cares for them) in hopes it will buy time to complete what he needs to do before finally arriving and settling the situation himself. I’ve suggested before that he could be finishing reading Ben’s journals, which is a good enough reason why A) he was able to build a new lightsaber and already put it in R2, B) how he seemed to have gained significant wisdom since ESB, and C) why he wasn’t there with the others at the beginning of the rescue. Then, lastly, it would be helpful if there could possibly be some new, small bits of expository dialogue between 3PO and R2 while they journey to the palace, so the audience understands the (aforementioned) current situation better (again, I already suggested before some potential lines).
I doubt that the rescue sequence could ever be made to make perfect sense, with the limitation of available footage, but with certain changes and the imagination, it sure can make better sense 😃