In the book:
Indirect Fire requires no line of sight and Artillery does require line of sight.
I strongly feel like this should be the other way around. As weapons like catapults and bombards arent really aimed towards enemies you can see, but rather at a "grid coordinate"in a genral direction (artillery), while flat trajectory weapons like ballistas and cannons are more or less aimed at their target, but may still be lobbed over other things (indirect fire)
Tl;dr indirect fire/artillery is on the right weapons, but the rules text for the abilities may need to be swapped