Vivian's shield only protects in front of her, use a flank champion such as Skye to attack her from behind. With any champion you should still try to attack her if doesn't notice you.
If Strix catches you, you're dead. Run Fluffy 5, Symbiotic 3 and Harmonious 5 to save yourself from a headshot and a 2nd bodyshot. Or run Fluffy 4 and buy Haven if you're confident he won't land a headshot.
Bait Torvalt into using his Recharge by activating your shield, deactivate your shield and hook him, it will stop his recharge and not reset his cool down, leaving him open to damage for a long period of time.
Viktor can easily penetrate this front liner's shield, and his grenade has a big enough radius to damage anyone behind Barik's shield. Also, Barrage can easily be used as a flank Ultimate like Skye's, and can kill Barik's team if they are close.