I have a stack (somehow managed to buildit by selecting 3 characters inside the city) and want to attack a spider. Of the 3 characters in my stack, sovereign (first in stack?) has 0 attack while both other characters have swords. I have a total rating showing 8 swords, so I should be able to attack but can't, probably because the sovereign has 0 sword? The game provides  no feedback when I click on the spider as to why I cant' move there. I get the regular swords icon meaning I expect to be able to move there and fight, but am not allowed to.