I don't get your post Brassneck the semi finals are two legged and does it really matter who gets through first
As I said, not life or death.
It DOES matter who gets through first, especially if there's a large gap between that and the 2nd qualifying finalist. Hotels etc tend to get booked up very quickly once a team gets to Wembley. Furthermore, the shorter the period between qualifying and the actual game, the more difficult it becomes for fans, clubs and indeed sponsors to make arrangements.
Not sure what your point is about the semi final? We are supposedly playing our QF when the other teams are playing their SF. Therefore, when they play the 2nd leg, we/Liverpool will presumably be playing our 1st leg.