A Question for OOO: Plurality from Singularity?

I have been reading a lot of metaphysics recently when I came across a question that stopped me in its tracks as I intuitively asked it of object-oriented ontology.  Before people get up in arms, treating it as a ringing challenge, please understand that I am trying to work through the thought rather than beating anyone over the head with it.  

If everything is an object, as it is the only ontological category, then how do we explain the plurality of being?

This seems like a blatant contradiction, or at least a paradox.  Since I prefer questions to which I already have answers, which locates what I think I might mean by the question, let me offer my first guess at a response.  "Object" is the only ontological category, but it is not the only category of analysis.  Here, I invoke the distinction between an order of being and an order of analysis that is analogous to the real vs. formal distinction.  Then, we may explain plurality in terms of orders of analysis.  

However, my first answer may not be sufficient, because it proposes that our analysis offers very little explanation of real difference.  But then, is that not the point?   Is this not a "flat ontology" that claims ontological parity?  Returning a counterpoint, we cannot we have "flat ontologies" of more than one category?  That is what Peirce, Dewey, and Buchler have.

Levi Bryant uphold "power" as a category; we have discussed it and it appears in his lexicon, while it is a point of difference with Harman.  Powers form part of the irreducible core of objects on his view, and are generated and generative.  Given that and our discussions, I suspect that he has an answer.  I am less sure that Harman does.

Can a person more informed of these thinkers clarify these problems?  Or am I on to something, the product of seeing things "sideways" as a pragmatic view appears to offer to these debates.