Ok, I don't understand why the Steel Ovens are considered to be so powerful?
They might be powerful for a nation that already has a forging discount on mages that would stack, but otherwise? Judging from the Wiki Page on forging, we have:
Code:
Magic Path Level: 1 / 2 / 3 / 4 / 5 / 6
Normal Gem cost: 5 / 10 / 15 / 25 / 40 / 65
Steel Ovens: 4 / 8 / 12 / 20 / 32 / 52
Steel Ovens + Dwarven Hammer: 2 / 5 / 8 / 13 / 22 / 35
ForgeOfTheAncients: 2 / 5 / 7 / 12 / 20 / 32
So you have one province where forging is slightly more expensive than having ForgeOfTheAnciencts
without Hammers, but if you have FotA you are likely to use DwarvenHammers on top. Also, I think the main bonus of FotA are the reduced path requirements, which the steel ovens to not provide.