It might require a bit of a rework of the items to fit cleanly I suppose, but I was looking at the items and that feels like it could be a pretty natural upgrade path- often if Im taking soul shredder and mystic shot, it feels like you're forced to get rid of one as you get further on even tho theres only a few spirit related orange items to scale with. I think overflow is a good item but often not your first pick for t4- I see far more crippling headshot there- and combining the two might make them feel better due to slot econ.