I see... in both teams I have venusaur with mega chari Y so both pokemon are necessary.
My first team was: Mega Chari Y, Venusaur, Cresselia, Heatran, Hitmontop and Ferrothorn
My second team is: Mega Chari Y, Venusaur, Sableye, Scrafty, Rhydon and Aegislash.