i)Sting overpowered a city buster attack from a city buster canon with his roar in "Twin Dragons of Sabertooth".His roar should be stronger than that attack to overpower it.I brought this to prove Wahl can do better feats.I know that Acno didnt oneshot country, but he still destroy it with his power, not hax like Brandish or Dimaria.
When August and others destroyed a country? They just go across country and maybe kill thence people (in manga Worren said that 1m army go from east, I think it was mistake but what if not?).
I didnt say that Wahl is not city lvl, his etherion maybe can blow city. I was argue for another points.
And where in hell Sting is city lvl???? On GMG he was weaker than Natsu who is not city lvl.
Other people said that.
As you say Wahl etherion is mountain lvl (well mountain is equal to city, but if mountain needs strong attack, city needs huge aoe), than Gildarts must be stronger than him. Etherion is strongest spell of Wahl while Gildarts blow low-mid mountain with simple punch
ii)Destroying a mountain takes more energy than a city.According to powerscale
Mountain level>City level>Town level>Multi City Block Levels.