Yep, I'm actually an Elf sage with a 3 raw wpa and 120% magic science (and then the +30% effectiveness from being an elf on top of that), and I've noticed that in war I can't do very much at all, even against avian/human/dwarf pure attackers.
It does seem to be somewhat limited to war and hostile relations, since OOW I have little problem. Hell, I even failed casting CB about 5-6x on three different targets, none of whom were mystic in war!!! That's freaking unbelievable. Clearly failing a bunch of times casting CB against low wpa targets means something is wrong...