@Menachem Shmei
first of all, most rishonim and the gemara holds it IS avoda zara for all – bferush. (any svara to be mchalek????????)
Second, if the overwhelming shitas hold the world is flat – does that make it flat?
the fact is that shituf is denying God ENTIRELY and is the SAME as ANY ancient avoda zara who viewed the god (sun, rain etc….) as manifestations of the supreme power.
if god is a creation, then how do you know he exists – who created him? He must be the creator of all creation. if you think he is a creation – you are ENTIRLY DENYING the creator – exactly as ALL ancient avoda zaras.