i'm not sure i understand what you're showing in the top pictures. 'top layer of dust will be disturbed' means...? as for the bottom pictures, it will be quite easy to attack these now that we automatically have access to the higher ground. there's numerous strategies to attack lower levels of structures, ranging from simple arrow potshots to surgical TNT strikes.
ppl were conserned that burieing the cities would make some of the buildings hard to see i just wanted to show 2 of the shortest buildings so ppl could see that they could still be found and as to the dust insted of it being perfectly flat there will be dunes and random small holes. Finaly as to the difficulty untill some one can show me a viable method using the mods CAruins and Atomicstrykers Ruins i say there is no perfect way so this is the best we can do for now