So, in conclusion:

Solving for 3.00 multiplier(5 step radiance, according to Saevel, couldn't find source for sc modifiers on radiance/umbra personally):

7.042432 with 4 wsd

7.103096 with 3 wsd 1 scd

7.14288 with 2 wsd 2 scd

7.161784 with 1 wsd 3 scd

7.159808 with 4 scd

Solving for 2.25 multiplier(6 step light/dark):

5.651824 with 4 wsd

5.684822 with 3 wsd 1 scd

5.70216 with 2 wsd 2 scd

5.703838 with 1 wsd 3 scd

5.689856 with 4 scd

Solving for 2.0 multiplier(5 step light/dark):

5.188288 with 4 wsd

5.212064 with 3 wsd 1 scd

5.22192 with 2 wsd 2 scd

5.217856 with 1 wsd 3 scd

5.199872 with 4 scd

Solving for 1.75 multiplier(4 step light/dark):

4.724752 with 4 wsd

4.739306 with 3 wsd 1 scd

4.74168 with 2 wsd 2 scd

4.731874 with 1 wsd 3 scd

4.709888 with 4 scd

Solving for 1.5 multiplier(3 step light/dark, 6 step fusion/grav/distortion/fragmentation):

4.261216 with 4 wsd

4.266548 with 3 wsd 1 scd

4.26144 with 2 wsd 2 scd

4.245892 with 1 wsd 3 scd

4.219904 with 4 scd

Solving for 1.25 multiplier(5 step fusion/grav/frag/distortion):

3.79768 with 4 wsd

3.79379 with 3 wsd 1 scd

Given you use the listed set:

-Our breaking point in this set is 1.25 multipliers. Anything above that will derive some value from at least one piece of SCD+6 gear being used over an equivalent WSD+5 piece. So, light/dark if not 2stepping, and t2 sc only when using 6 steps+.

-Step 5/6 light/darkness/radiance/umbra will favor 2-3 pieces of SCD gear, with the optimal set shifting toward 3 pieces as you go into higher steps/radiance.

-Allies roll will push 4 SC pieces to the best setup for step 5/6 light/dark/umbra/radiance, and likely increase the amount of pieces you should use on earlier steps as well.

If you want exact results for a set with different amounts of WSD/SCD, use the formula to calculate it. Doesn't seem to be a worthwhile swap to me, but it can be technically better and this killed a good half hour so have at it.

edit: Fixed numbers for valorous gloves' scd, and cleaned up points. Keep in mind that if the SCD on gloves/cape goes into the job trait instead of the same term as valorous, it makes SCD valorous more effective.