If everyone is complying with their allocated time why would we need 50 minutes?
It appears they aren't. The reports I've just seen indicate that there are many non-conformers. It was stated at RAPAC last week that Perth had a non-compliance rate of 25%, Sydney 7%. The extra holding at Perth is a result of the non-compliance.
Now you are being dumb on purpose.
No, I was simply pointing out that you cannot provide a decent landing sequence relying solely on landing slots; your words "If I have a published slot time to land in PH then that is my slot." I cannot guarantee achieving my touchdown time within 5 minutes, let alone a few seconds needed to get a tight sequence, and nor can you. You said "mixing two systems" and I said we
must have the two systems: the axe-chop rough COBT at the takeoff end and the Feeder-Fix to-the-10-seconds (hopefully) at the landing end.