Why would Sasuke have different techs then the techs that the rinnegan is suppose to grant the users?Sasuke doesn't need anything new, but Naruto sure does.Sasuke has tons of different jutsus, but kishi has only gives naruto variations of rasengan.
Just like you stove the english language.
Sasuke need's something new without a doubt.
With the EMS powers he possessed he would already be weak against Madara, he would've been 1 shot.
With the Rinnegan it wouldn't make any difference, Shinra Tensei is not even going to effect Madara, he won't even have the chance to use Human Path or anything, and Chibaku Tensei is just a waste of chakra, considering Madara will also easily escape that.
The fact that Sasuke has a new Doujutsu from the Juubi itself was really needed, without anything else he wouldn't EVER be able to dare oppose Madara, or even be close to on par with Naruto.