Would the UK be hit tactically by a couple hundred warheads or would be just be wiped out completely?
I don’t think anyone ever bothered with getting things to the “VAPOURISE EVERYTHING!!!!” stage.
Major cities, military bases and industrial areas would be hit, on the basis that the country’s effectively put out of action by that point. Everyone else can die slowly.
Very pragmatic, these military planners 😐 . Same reason they use 5.56 calibre these days – the older calibres would go straight through people on a fairly regular basis, often killing outright. 5.56 tends to bounce around in the torso, so you end up with more badly injured casualties. Casualties are a good thing, as you’ve then got 2 more men tending to the casualty, plus even more men operating and providing logistics for a field hospital, or he has to be ignored and that saps morale.
There was an interesting documentary with Robert McNamara on a few years back. He was an expert at the appliance of science to killing – he was on about how Japanese houses are made of wood, and his plans to use incendiary bombs wiped out more than the atomic bombs did…