Not to be pedantic or anything but isn't it "Cleared to Land" as in "You have clearance to Land" and not "The runway is clear for you to land" as "Clear to Land" would suggest? The former would be ATC's part of the exchange and the latter would be the pilots' responsibility. Just as "Cleared for the approach" can be issued to more than one aircraft at a time, "Cleared to Land" shouldn't be much different.