Lightless lanterns aren't so fast to reach at constr-6 imho... Maybe with your build you can do a lot without mages in battles, so you don't need to rush up evoc and thaum, and you can afford that drain-2 with which your mages fatigue 20% more in battlefield spells
But if you went to evo-5 instead, you would have had mages casting Flares and Fireballs and Fire Clouds and Falling Fires on enemies and around your fire-immune troops soon
