On their own, no. But the problem of knowing where Skavenblight is, especially if it has been known for a long time, is that it wouldn't just be Tilea or Estalia wanting to burn it to the bedrock. The Dwarfs, tons of the Border Princes, Bretonnia, and even Ulthuan would be eager to turn the Skaven capital into a smoldering crater if only they knew where it was.
If it was a case of "It is known by a rare few on occasion and the Skaven keep killing them" then that would be another matter.
They would not.
Unlike the empire, who is secretly at war with them, the rest of the world has been openly at war with the vermintide either for centuries or millennia, they've had time to capture and interrogate everything they could ever need out from Skaven prisoners or found from their own maps. Skavenblight is known but that doesn't make it attractive.
It is the most populated skaven settlement in the world while also being garrisoned by some of the most elite and well equipped forces their species has ever produced all surrounded by a swamp that is constantly being blighted by the grey seers, clan pestilens and the great horned rat's presence.
The dwarves are so anemic they can barely try to take back Karak Eight Peaks much less try and destroy Skavenblight.
The Border Princes have no central government and their military forces are laughably organized and under equipped.
Ulthuan does not have enough lives to both maintain their current commitment in holding back the dark elves and other chaos aligned forces all across the breadth of their naval empire and try to take Skavenblight.
Brettonia already has enough on their plate with the Orcs and Vampires constantly trying to destroy their country along with constant pirate activity along their coast it not to mention that the swamps surrounding skavenblight basically render their cavalry nearly unusable.
The fact of the matter is knowing where it is does nothing because trying to take it would basically destroy whoever wins.
The reason Vampire El Duce can pull it off is because unlike those other groups he's fanatical enough to get it done no matter how much blood needs to be spilt and more importantly unlike every other faction he is both a powerful necromancer and the leader of an army's worth of powerful necromancers.
Put respect on the Skaven, they maybe chickenshit cowards who often hide their presence out of fear of being found out, but when they want to throw down they can do it with the best of them.
