Regarding artillery: I had a situation where a ballista (artillery) killed 3 devils, even though the hero was quite decent...
And as for towers during defense: there were times when they dealt almost 5000 damage!!!
P.S. At first, even my friends didn't believe it until I showed them the save file... :)
That's why the defender in the castle cannot have a ballista:)
P.S. You need to be more attentive!!!;)