I'm not sure, but I think in AoWSM some abilities for forged items are dependent on the researched spells. It's true that only weak items can be created (I usually create one with Casting Specialist to get these 10 extra channeling points), to get a more powerful item you should explore some ruins or complete a quest.
In MoM you can create so powerful items that it can be unbalancing, if you equip your heroes with them it makes it too easy to conquer the world.