And Orochimaru. A Sannin. A legendary one.
Aside from the MS, what has Kakashi shown with his Sharingan that would trump Sasuke's Sharingan just so easily? Kakashi has been seen to not do well at all against another skilled Sharingan user. And by skilled, I mean full blooded Uchiha skilled. One of the reasons why the MS is probably the only thing that makes his Sharingan strong.
He definitely has more experience, naturally. He's older.
Tactical edge? Maybe. If Kakashi were in Sasuke's shoes during the whole Orochimaru thing, do you think Kakashi would have thought to paralyze Orochimaru? Not so sure.
Justu's which drain his chakra and stamina like crazy. Remember when Naruto first came back? He and Sakura teamed up against Kakashi to get the bells again. By the end of it, Kakashi used too many large jutsu's, and was worn out. And you saw how in still great condition Naruto and Sakura were at the end of that. Imagine Sasuke. Tons of jutsu's aren't always that great if you don't have the stamina and chakra to use them effectively.
Much like the only way Kakashi could win is by using MS on Sasuke. Actually connecting with it. Assuming Kakashi has gotten some practice in using it. All he was able to do was remove Deidara's arm, no? Pretty lame for a MS ability if you ask me. I'll assume he hasn't had much time to perfect it, and with Sasuke's speed, I doubt that Kakashi could use it effectively against him. Also, Sasuke's speed is right at Kakashi's level, or he's already surpassed it. So Kakashi's speed wouldn't be much of an issue for Sasuke.
Which isn't always on. Deidara was proof of that.
Why not? Deidara did. Rather, he wasn't totally caught in it. Sasuke is much faster than Deidara, and would be a hard target for Kakashi to focus on. He'd end up wasting MS and chakra quite a bit trying to hit someone who's as fast, or faster than he is.