[ReptileMan]

>payload to kill everything in a 50m radius for example.

cluster heads solve this beautifully because 1kg of high explosive kills everything good enough in 5 meters radius.

[XorNot]

Which is still nothing in terms of area lethality terms.

For comparison, the Excalibur GPS guided artillery shell was considered precision because it would hit within 5m reliably.

Compare to the lethal range of a 155mm, where the kill radius is 50m and casualty at 100m.

[ReptileMan]

155mm has payload of around 7kg.