805.6a say that if an effect allows multiple players to draw cards this is done in APNAP order but within a team members of the same team do it in any order they choose.

If I understand the rule correctly, in an TwoHeaded Giant game if both players on a team have an Underrealm Lich on the battlefield and draw a card at the same time they have to choose an order. And the first player will not know what choices will be offered to the second player because the second player cannot start looking at cards until the first player has finished drawing as replaced by Underrealm lich’s ability?
What happens if somebody casts vision Skeins? Do the get an option to first let one player choose a card then the other, then again player 1 and player 2. Or do they have to each make two choices one after the other before the second player on the team is allowed to start drawing cards, I e, look at top 3 two times because of the Lich?