For crying out loud, they're talking about his deliverable nuclear warheads, not his artillery. He's got two of them already, and he's going to be able to start mass producing them within the next several months.
Nope, you're incorrect; all of the articles I'm referring with insane civilian casualty totals to are referring to civilian casualties caused by conventional artillery firing explosive shells and chemicals.
The main problem with most is that they take the figure for the TOTAL amount of artillery North Korea has, and the number of shells they can fire in an hour, and then assume that EVERY single artillery piece can hit Seoul; this is incorrect.