so far i know the mobs and Fortification lvl should be around lvl50-60 i dont know what you want to Skill on the Campaignmobs but you should skill up with FoV or GoV and the right enemy lvl for your current skill and the extra spark points on Killing Mobs + Zonequest and all the other stuff gives you a much faster lvl up way as the silly Campaignsystem thrust me...
in Campaign you wont have the time to Skill up properly and you only can do the 500+ dmg quest on them the dosn even count as a monster kill....