Now that all resource cost reductions are now multiplicative, they now will save less resources that they do on live assuming the math is
base * (1 - cost reduction 1) * (1 - cost reduction 2) *....
instead of the current system which I believe is either

base * (1 - cost reduction 1 - cost reduction 2 - ...)
OR
base - ((base * cost reduction 1) + (base * cost reduction 2) +...)

Before it was constant off of base where the resource saved is by value the same regardless of how many cost reduction passives you have. x% of base is always the same.
Now x% of base isnt always the same value. it is now x% of base * y% * z% *....

This means an effective nerf for any race with a cost reduction passive especially when you stack cost reduction sources.

Let me know if my math is faulty

Thoughts?