I think in terms of skills and technic, Sasuke still lack behind
his older brother unless Itachi ‘allows’ his lil brother to kill
him. Not saying sasuke cannot surpass itachi but maybe not yet. I
have to say sasuke showed quite a skill there fighting against
deidara but against orochimaru then, if oro wasn’t that sick and
near to dying, he probably would have taken over sasuke and kill
him (But ALL of us know this will never
happen no matter how strong oro could be because this is
NARUTO, the 2 mains of this anime should been
naruto and sasuke ba and they still need sasuke to carry on the
story.)