Fernando isn't the best at killing, but he can certainly pump damage. Working on the point, always fireball and flame groups, and charge into them to get behind them. Use the Scorch legendary to deliver as much damage as possible into groups.
While Maeve is best at flying around an open map, a closed environment doesn't hinder her performance. Use Prowl to speed around corners, and jump INTO corners to confuse the enemy.
If you happen to come across Khan, use the environment to your advantage. Get hits from a distance, run around, and get more hits on him. His relatively small shield lets you get more shots at him, too.