That's not a very precise analysis. SK is vastly more developed than the north, including militarily. The only reason they don't have nuclear weapons is that they're under the US atomic umbrella. They could develop nukes very fast if they wanted to (as could Japan). While NK has crazy numbers of infantry soldiers and tanks, pretty much all military hardware of South Korea is vastly superior.EDIT
To consider is that the position of NK and SK is not that much differing !
Both resent the countries bordering them and the former colonial empires incl the US now.
Both are very dedicated in strenghtening their countries position by strict discipline, low indulgence, helped by their traditional culture element of very long term thinking.
Both were underdeveloped countries back in the 50ies last century.
SK was positioned to go for the economic focus and NK for the military focus.