Stacking abilities doesn't do much.
The more of the same abilities u have, the worse they get.
For example: 1x +Attack might give you +10% more damage, but the second one will only be around 7% more damage.
You should try to go for different ones, not for the same ones.
Edit: Also the gear doesn't have the same abilities when u order it. It is completely random. Only the visuals are the same.
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