[calmon]

To bring up the first RAND game:

Micah (Fomoria) imposing used 2-3 SC strike forces beaming to unprepared castles, cast the underestimated spell "Crumble" one or more times in the same turn (the spell is even cheaper with CBM) and stormed one turn later.
The defender had exactly 1 turn to do something. Perfect targets are non-air/astral nations which normally can't react.
His own castles were nearly impregnable. He just waited untill someone was ready to storm and beamed defence in.

Well to be fair there are counters but its not as difficult as many people believe to take out numbers of castles in a short time in the late game.