Quote Originally Posted by Yula_the_Mighty View Post
With two types of ore it was a hassle getting the right mix. I always ended up with way too much of one type. When I mine, I would end up getting even further out of balance.

It never made any sense that tier 6 had four kinds of ore, two kinds of hides and two kinds of wood. It seemed like Turbine thought about creating two crafting tiers decided latter on that there would only be tier 6 instead of tier 6 and tier 7.
IIRC, that's more or less what happened. Siege of Mirkwood didn't add a new crafting tier (T7 is Westfold, from Rise of Isengard). I don't know if Mallorn was added then or if it was already present with Moria (I tried to research this, but info from circa 2008 is unfortunately hard to find), but basically Supreme crafting was the top tier through two expansions.