There is a longer version over at Board Game Geek but I thought I should post the short version here if anyone is trying to keep track of wins and losses.
Yesterday we finished our SoB campaign, ending with a Overlord victory. I was playing the Mistress of Serpents and the Shadow Queen and I won through cities, destroying five of them. The heroes had a pretty good group, most notably they had Thorn without which they would have lost weeks ago. We had all expansions except ToI.
My tactics as an Overlord was to get as many LTs in play as possible and siege everywhere. Simply fleeing if attacked rather than taking any chances with them (which often mean running in the first turn). In copper the heroes could not do much against this, they drove of Soriss a couple of times but even with just two LT they could not stop me from claiming at least one city in this way. In Silver things got worse when Kraken started sieging as well, and more cities fell. The Heroes eventually got the silver webb item and Thorn proceeded to teleport to the Siren, kill the spiders protecting her and then webb her for long enough that the rest could reach and kill her. Still Kraken and Soriss sieges different parts of the map and just fled one step if the heroes attacked. Eventually the last city I needed fell and I had won.
All in all, the worries some people had about LTs sieging at different parts of the map and just fleeing if attacked was totally correct. The heroes clobbered me in dungeons (when they bothered to go down there, they concentrated on the map instead) but there was no real counter for this overland strategy. With the Count or Bones it might be different as they only get one LT in copper, but with the Mistress of Serpents is pretty much game over from the start. Only Thorn gave them a chance.