What are the rules regarding meeting prerequisites for Talents acquired from a character's Archetype? Must they fulfill them as they would if purchased with xp?

I go through the Race and Archtype steps in Character Creation without any regard to prereqs. When the Heretics get to use thier 500xp (Marine) and 1000xp (Human) to purchase additional advancements, then the prereqs take effect.

It can be viewed in one of two ways -

1.The character gets those talents and traits for free, regardless of meeting pre-req.

2.The character archetypes are built in such a way that they SHOULD meet the pre-reqs and any that don't are more of a game design issue, so should be ignored.

At no point would i force players to buy pre-reqs. Starting XP is designed to allow customization of character, not to force everyone using a certain archetype to spend it on the same things.