At many airports (in the US), giving multiple a/c clearances to land
without the runway being clear is not unusual. The controller is betting
he'll have the required clearance when you get there. Most of the time it
works out. Sometimes not shrug.

The controllers at one of the local Class D airports in southeast Florida
have a reputation for being rather cautious--and not doing that. (That's a
deliberate understatement, although there some extenuating
circumstances--including a high volume of IFR traffic.)

I strongly suspect that many (perhaps most) pilots pilots usng that airport
would be much happier with a quicker flow of traffic and more frequent
go-arounds.