Depends on buff setup of each and other stuff too.
For example, if Necromancer has his pet summoned, more chances to win are with necro, but if Necro has no pet summoned, SPS wins.
Also, after Kamael Throne, resist buffs get more common (Eventho they still work on other chronicles) and most of resist buffs are for Dark Attribute.
This means that SPS will have for example 70 Dark Resist and Necromancer will have like 40 Water Resist, this is a big advantage for SPS, so yeah SPS will easily own Necro.