Have your main use shadow clones its much easier to do combos as the clones have a chance of low floating.
sasuke also has low floating. You also need between 3-10 hits before the combo starts

low floating -> sasuke -> repulse -> hinata -> knockdown -> hinata -> knockdown -> kabuto -> 10 +hits -> sasuke + main

I manage to get a 7 combo off this. Its much easier with 3* sasuke or kakashi