Hiding in a crowd / Hiding behind multiple creatures

When it comes to stealth, 5e is very vague on what can or cannot be done.

If we refer to the rules as written:

You can’t hide from a creature that can see you,… (PH. p177)

This means that being in partial cover doesn’t grant you hiding potential since others can still “see” you.

So following this thinking, you couldn’t hide behind a target since you would get half cover and could still be seen. What about hiding behind two consecutive targets? Could a DM rule that it would provide an improvement toward 3/4 cover? But then again, one could still be seen since it’s partial cover… But what if you are behind multiple (3+) consecutive targets? At what point can we say that you are behind enough covering targets to provide a total cover?

Imagine an Assassin’s creed type of scene where the hero is concealed and breaks line of sight by hiding in a massive crowd. It would definitely be an interesting scenario but the rules on hiding as they are make it difficult.

So my question is in two parts:

  • Do you think by some DM ruling, it would be appropriate to allow multiple creatures to provide enough cover to completely hide someone?
  • What would be a balanced ruling to permit such stealth play?