i think you should wait and power up more

I agree with the above, and yeah 2 star Shikamaru can help you a lot concerning controls at least in your stage.

i now have 6.5k and 2* shikamaru but still can't beat them i followed the exact tactics of a vid i saw and tried over 50 times and no success

the guy in the vid had lower power than me

I would go with Hinata, Gaara and Shikamaru.
Use Hinata to tank hits in round 1.
Take Bani Chakra passive (to get extra chakra), if you are at that level.

In round 1, you start with Hinata. as you get chakra use Shikamaru to control Guy and use Gaara´s barrier (if you have Bani Chakra).
In round 2, use Main´s mystery on Lee and control him. Once you get chakra, hit them with Gaara.
Rest of fight should be easy.

If you cannot take Bani Chakra (you are low level):

In 1st round use Hinata to tank damage and Shikamaru to control Guy.
In 2nd round use Main´s mystery to control Lee, and Gaara´s barrier with remaining chakra.
In 3rd round (if you have Oboro clone use Main´s mystery again then get chakra and...) Hit them hard with Gaara.
In 4th round use all available mysteries... by this round, you should be either done or just finishing last drops of their pathetic resistance.

I wish you luck and happy progress :)

most ninja exams (especially the early ones) are not about strategy but about raw power.

well, any exam where you dont have to deal with element puppets can be solved by raw power without strategy :D