It’s worth taking Wisdom, but not always. You shouldn’t take it on Jebus maps because all the books and Wisdom might simply max out the skill. It’s also not worth taking less of it on M maps because the chances of finding such a Pandora’s Box are low, and the chances of building a Grand Mage above level 3 are even lower. You can take it on maps with Dungeons, and also on maps where there are computer players; they like to build all sorts of random things in their castles.