At risk of straying away from the mechanics of it, I have read in several places that Blizz have deliberately kept the stats more generalised on the more entry level raid gear to allow more people to gear up, therefore most items that drop for a specific skill eg tanking will be needed by all tanks. I suspect this will change with higher level gear and patches.

It's going to be difficult initially to really tweak gear until a player gets more drops with varying stats on them.
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