To invisible overlord.
You ever get down here real close and study one of these walls? The bookeepers always say it's a cube for the paperworks sake, but to make those walls they just hammer it really really really thin. It looks solid enough with just a glance over, nobody ever really notices it's only a few nanometers thick so the gobbos never bother to try knocking it down.
Besides you ever see one of those goblins with a whip? They are like bloody lightsabers, they impart so much blunt force on such a small point yer going to need candy to have even a hope of resisting that. Me armor is only as good as the metal it's made out of mate. Get me some metal capable of taking a velocity multiplier five times that of a shortsword on a point a 50th of a shortsword's blade tip and I might be able to do something for ye.
Urist McArmorer
Dear Urist McArmorer,
Are those thin walls somehow managing to fool the volcano? Because iron walls and floodgates are currently holding back a few million Urists of magma that would otherwise be flooding your forges. Maybe the walls are thin, but they stop flying boulders, ballista bolts, giants, collossi, and the aforementioned dragons. Urist McBlacksmith can be making them out of tin foil for all I care, he gets results.
And it's not just the whips, poor Urist McMarksdwarf was crippled by a kobold with a dagger while wearing steel chain. Made by you.
One more thing... Yet another axedwarf is yelling at the mayor right now about being "embarrassed to be uncovered lately." He is wearing, among other things, a steel breastplate, a steel mail shirt, steel mail leggings, steel greaves, steel boots, steel gauntlets, and a steel cap
and steel helm. I shouldn't have to ask you if you are making crotchless armor!
Sincerely,
Your invisible overlord