I only see the Red Skulls losing 3 cities... And lets not get too cocky here
they're not even in the top 20
The Immortals took 8 cities from The Red Skulls (Edgar The Nigg, Ballz81, Wolves1949, Demonjuggalo, Leovak's first city, Skubs, Staciekins, Mammothon)
The Immortals took 3 cities from The Red Skulls Cave (xCyanidex's 2 cities, Dilious)
The Immortals took 1 cities from TheRedSkulls (One of Mac of Loki's cities)
That's a total of 12 cities.
Most of these players were kicked when they lost their cities, but you can find any of them on grepointel.
The Red Skulls were ranked 16, in the overall alliance rankings when the war started.