I remember pictures from the Vietnam War showing them dropping a full load, though they would roll out one at a time. They would land in a line along the flight path with not a lot of safe space between each one.
Precision guided bombs can be steered a bit, though they have a very steep glide slope. They must be dropped somewhat directly over the target, considering wind and initial airplane path. They are VERY accurate. During the Gulf Wars, cement bombs (no explosives) were sometimes used to take out tanks nestled between civilian buildings.
This makes me think that they would be dropped one at a time, or in small groups.
Wouldn’t a few nukes be cheaper and more effective?