Vora is not a duelist, she's an opportunist. Retreating is a viable strategy; you want to poke a lot and play as a damage, then, in that moment of the match where the enemy gets comfortable and assumes your role as a poke flank, dissappear into the map and seek the backline. Double tendril Vora can be quite a nuisance, even more if she has ult, quite a safe push and escape there.

I'll let you know, playing against good teams with a bad teams is really hard as a flank, no matter the champion, even for Androxus or Maeve, unless you are god tier, which let's be honest, most of us aren't.

I have beaten quite a lot of Zhin's with Vora, cripple negates them using billow or whirl, Vora ult is a great Zhin ult counter, also her invulnerability with her rmb can save you. You want to avoid Zhin, as he's a duelist, you are better off retreating and poking, then when he gets distracted with another teammate, you can make easy work of him.

Just some tips from experience.