You can stop her poison and his poison bomb with neji. Unless it doesn't work on the hard difficulty.

Here's a group I had for SA. We beat it 3 in a row with no issues.

Raz's Team: Gaara, Kiba GNW, Shizune and Water Main (using healing and clone)
Jonny's Team: Kabuto, Kakashi and Neji; Midnight Blade
My team: Kabuto, Neji and Sasuke. Water main (Healing, whip, clone, water boost and the shark bomb that does repulse to low float); used the chameleon/deer/gamachu. If gamachu, use Chakra Dissection Blade.

Probably not the best teams, but they worked and we had a run where Shizune never healed.