Retired controller here, retired for ten years at that. A while ago, the FAA big wigs said the local controller could not lock and load the runway unless there was another person monitoring that position, and that position only. I am guessing, if this controller was on the ball, issued that clearence as that aircraft was approaching the runway. In PHX, most everything there is 6,000 feet airbourne, which will get you three miles of seperation. Evidently you are not a heavy. I will never forget the day this rule went into the books, working the mid at LAS. we had delays left and right till 1am.