As for the claim that the monsters in the Dungeon are stronger on a random map, I honestly hadn't thought about it... is that really the case???????
I'm somewhat skeptical.
I've seen all sorts of things on random maps, even when a horde of snipers stands on the surface near the city exit on the ONLY road, guarding an artifact and preventing you from going around. This is practically a guaranteed loss.
On the other hand, I've also seen Dungeons where there are no strong Orcs around the city (I always set the "strong" monster-neutral level when creating the map).
I created 10 random maps, where one player is a Castle (at the top), and the other is a Necropolis (in the Dungeon).
On the surface, strong monsters were present on 3 maps;
in the Dungeon, strong monsters were present on 7 maps (in 3 of them, the Necropolis had problems with exiting), on 2 maps they were weak, and on one map, there was almost no Dungeon at all