I'm having some trouble using offensive spells in battles. I'm not quite sure why, but given where my casters are, I'm having trouble seeing the right opportunities, and spend most of my time casting defensive spells. Right now I'm playing vampire counts and the only offensive spell I use with any effectiveness is the early one that is good against single units (I use it to kill lords and heroes). Otherwise I'm pretty much just healing (which, by the way, is pretty darned effective, and gobbles up plenty of power).
The descriptions of the offensive spells spook me- poor penetration and best high angles, etc: I'm not sure what these even mean, but I'm assuming I can't use them when my caster is behind a line of my own troops. That could be wrong, as I see don't these terms defined anywhere, and I've looked.
Anyone have more success? Are there any good guides out there on this? Most I've seen are junk.