This would be awesome to watch.
Though I think Sakura would be in the edge of her life in this one.
Naruto and Sasuke though can beat up the three.
I think there's no need for Sakura.
I could see it now.
The Legendary Sannins and Team 7 face to face in the battleground.
Each Student runs towards their masters and the Sannins would counter each blow given.
A scene would show up Sakura being pushed to her limits by Tsunade and was hit heavily by Orochimaru.. Only to be saved by Sasuke.. and Naruto.
Naruto gets Sakura to a safe place, leaving Sasuke alone.
Sasuke alone versus The Three Legendary Sannins with Almost Half Chakras and Damaged Heavily during the early part of the battle.
Both Sides dealing blows, Tsunade gets heavily injured by Sasuke's attacks, though Sasuke is wounded by Orochimaru.
Naruto gets back to the field, together with Sasuke, they both face Jiraiya and Orochimaru.
Rasengan to Rasengan, Sword to Sword.
Naruto and Sasuke is far more powerful and the Sannins got defeated by Team 7.