A lot of the struggle is a combination of ninja available and the power you have. I was able to beat all but the last exam with the same team, but that is an exception rather than the rule considering that it was a well stacked S Itachi. A good way to think about it is what is it that your facing and how can i counter it. For the first round you are going to face mystery from Sasuke, Hinata, and Shika. Hinata is not a huge treat, so stopping or countering the other two is big, thus you want either a way to stop sasuke or break barrier, and immune to nerf the bottom team. From there its just planning your basics attacks and mystery to deal with the multiple threats. Maybe try a root lightning main with shisui and kushimaru and work from there?