I think that both the attacks happen when they are meant to, so things that normally go at initiative step 1 still happen then. Not too sure though, as it is worded pretty ambiguously.
"That which we foolishly call truth is only a small island in a vast sea of the unknown. For man to truly flourish, he must be willing to abandon the ever-shrinking island of such petty 'truth' and surrender himself to the reality of that which is beyond."
Dark Apostle Erebus, architect of the Horus Heresy