I used the term 'not that scary'.

In relative terms, that's true. Recall, I was in Strategic Air Command during the Cold War. The end of it, to be sure, but during the Cold War nonetheless.

To me scary is the Soviet Union's arsenal pointed and the US and the US doing the same thing right back.

The North Koreans have at best a shaky delivery system. Tests have not been shown that it is a reliable piece of technology (several have failed) and they don't have a lot of them. In the event of real tension, the actual number of these that could be used operationally would be low and there is also the reality tha they would need to survive a bombing campaign to eliminate them unless the attack was a low to no warning First Strike.

So no, the North Koreans aren't that scary. They have some nukes, but don't have a reliable way of using them.

You are right, by the way, in that the kind of weapons used during WWII are far from the smallest possible. The US produced tactical nuclear artillery shells for its 109mm SP howitzers back when I was in diapers.