Why Did the Nazgul Wait at Crickhollow?

[luthien-elvenprincess]

While re-reading the chapter "A Knife in the Dark", I am puzzled about the three Nazgul's patience at Crickhollow. Why did they stand outside the house all night, waiting until just before dawn to break into the house to attack? Why didn't they storm the house right when they first met together at the gate?
The Nazgul attacks at Crickhollow and Bree appear to have happened simultaneously. But what advantage was gained by waiting. Wouldn't it have been better if the three Nazgul at Crickhollow had struck as soon as they met up there and then hurried to Bree to help out there?

I would appreciate other's thought on this matter.