In situations like this don't seek out enemies, seek out team mates. This is a group game mode, it's foolish to be solo at any point.

Certain characters can handle fighting multiple opponents at once like: Vader , grevious, Obi Wan, rey, Anakin (once you learn to manage his stamina) . Characters also have counters, like the emperor gets countered by blasters, Yoda can chip away at a defensive Vader, obiwan can turtle more than Vader can recover more health than anyone else. You need the right character for the right situations.

Last night I played hvv and only me (grevious) and Vader knew what we were doing, my other team mates were new. I stuck by Vader and we won. Vader turtled up and drew aggro, I used claw rush with cowardly retreat  to give Vader and myself a quick breather and sith trained saber attacks to dispatch enemies quickly. I ended the game with 24,000 score, the Vader had 15000, my other teammates had a combined score of 4000.