I have also had a L9 hero have about three different magic traits, and not much else. A L9 unit should have at least 11 traits (not including race trait).
This, a big part of the problem is that champions pretty much never come with base stat traits. Sure its exciting to get a wildling hero that has coalstones, but the fact that hes lv 5 and has no traits beyond coalstones, Air I, Fire I and Mage means hes worthless till you get him to some evoker at level 9. Even the lv9 heroes need you to upgrade them just to grab some spellmastery or lethal traits.