Clarification: after revealing your starting site, you cannot reveal any card(s) that would lead to a violation of the rules for starting at a site as defined by the standard meccg rules or the DC General Rules.During the Draft, if you are allowed to play starting stage cards, you may play stage cards that are playable on a site, if these are playable on your starting site; when revealing such a stage card, immediately play your starting site with it (if not yet in play).
Nb. as per normal ME:WH rules, any duplicated starting sites are placed off to the side and returned to the location deck after the Draft; the attached stage cards may go to your play deck or sideboard.
see further discussion here and here