Basically, all woe are up to fast breaking not only euro in fact Doing any woe's includes Fast breaking, Luck and Strategy. That's the reason why guild maintains their castle's and as for solo breakers its on pure luck of being able to hit the remaining HP of the emp.
Well, Before, as I've remembered 7mos before i think it was on October 2011 or November there was a suggestion about this too and a certain GM gave an option of which they can transfer one castle from the american woe and transfer it to Euro Woe. Im just making this suggestion knowing that its for the benefit of all not only for me and you but for everyone. But, I wont get my hopes high but i still do believe that there would be a .001% chance of this being accredited. Its worth a try after all.