Well maybe you should fly something a bit faster!
Only half joking. The sequence is based on untouched landing times. Untouched the other aircraft might be beating you by a minute or two because they're cruising M.02 faster. Throw in a couple of aircraft coming from other directions (that you know nothing about) that happen to have untouched landing times in between you & the QF & voila! You need to lose time to fit them in ahead of you.