That's the main problem atm. During the preview, many of the gates had wolver stages so they dropped like flies. Iron gear, on the other hand, were much more rare.
With the current gates, iron gear is more plentiful (although with everyone crafting cobalt line that balances out). On the other hand there are like, 2 wolver stages among all the gates, one is in T1 and one is in T2.
I got three in one run. Just have to play the right levels and hope for the best.