All of you are talking about sasuke getting chakra by karin and zetsu, but your not taking into account of his physical state. his body was in shambles after the battle with A. A's physical attacks are the strongest in all of naruto, he defeated jugo with and elbow whilst he was in second state(bearing in mind he was weakened by A's Punch) also sasuke took a liger bomb from a which is one of a's mos powerful attacks.
Also i doubt his eyes were in good shape because he was using his sharingan from the time he infiltrated the kage room, too the time he escaped with madara, and wasn't just normal sharingan he was using susanoo's rib cage from the time he was fighting mizukage to the time he was fighting the raikage. sasukes physical state was terrible.
Its like when jiraya fought pein, his body would not do what its brain told it to because it was in such a bad state, i realize that they are two different scenarios but the physical state is just as important as the chakra levels.
sasuke did have trouble with danzo, but i think if his chakra and body and eyes were all at 100% he wouldn't have had that much trouble as he did.