Originally posted by Sinious
Thats %100 speculation as you try to guess what Lucas intended. Meanwhile in the story, Sidious has mastered both those specialities long before they became Vader's weaknesses which proves that Sidious did not reshape his mastery of his abilities to gain advantage against Vader.Vader never opposed Sidious cause he knew he'd get himself killed. Vader was really scared of Sidious and he did with good reason.
That's why I said ''Lucas'' not Sidious. That's why Darth Maul died with ridiculous way so Anakin had become Vader, that's why Yoda lost to Sidious, that's why Obi-Wan defeated him in Mustafar so he had become Vader, etc. all PT happened according to setting Vader right.
Of course Sidious never mastered these two abilities for gaining advantage against Vader. I meant plot of the whole series.