Impossible succession?

Man, I just don't get you.
2 aircraft were hijacked from each airport. They knew how to do it. They KNEW that hijackers don't fly planes into buildings. This is why we responded the way we did. They had the element of surprise. If they can hijack one, multiple 'teams' can hijack multiple aircraft. Please explain why you think this is seemingly impossible, because I sure as hell can't see it.
WHY?
Because THEY DON'T LIKE US. Why would you need it explained further? But just for funny-ha ha's, I will.
The timing needed to be close (it was FAR, FAR from precise) so that
A) The shock value would be increased. Every camera in the city of NY was on the north tower, then the second tower was hit on live tv with millions of people watching.
B) They left no time for a response from the military. If you hijacked two airplanes at 8:00am, by 10:00am every airplane in the sky would have known about it and adjusted accordingly. After striking their targets, what happened? FAA Orders an immediate grounding of EVERY aircraft in the sky. This would have included 2 aircraft which wouldn't have been hijacked yet, rendering them useless to the hijackers.
get it?
no, of course you don't. Common Sense isn't in your bag o' tricks.