There could be more than one intelligent designer.
Occam’s razor. No.
Got any scientific data supporting your suggestion?
C.S. Lewis put a lot of thought into the Eastern concept of duality, of a dual-natured god, or two opposing gods (good/evil), and ultimately concluded that it was inherently unstable, that one must prevail.
I'm terribly oversimplifying it.
Q.v., Mere Christianity, somewhere around chapter three, IIRC. Pity I waited twenty years to get around to reading it.