Except I disagree that
“one can be a Monotheist… while still acknowledging the existence of many gods”
as there are other terms for this, such as henotheist (which is the dedicated worship of one god without argument against the existence of the many gods). A Monotheist does not merely practice engagement with one god, they define their definition of the word “god” by the exclusion of other possibilities — which is a lot like what is happening now in these issues around the language in other theological discussions. Polytheism, meanwhile, does not argue against the existence of any gods, nor does it define itself by the absence of psychological archetypes or the sacredness found in Nature. Yet many Nature-based Pagans seem to take offense to discourse from hard polytheists on the reality of the gods (as if somehow the reality of the gods threatens the sacredness of Nature, rather than complimenting it..?) and Humanist Pagans do the same with their arguments, as if the reality of the gods dismisses the reality of archetypes.)
I have never heard a Polytheist argue that there is no such thing as an archetype or that Nature is not sacred and deserving of veneration. I have, however, heard both Humanist and Nature-based Pagans denigrate Polytheist acknowledgement of the agency and external existence of the gods, as if the reality of polytheism would somehow invalidate their own practices, beliefs, ideas, or identifications. But, as a Polytheist, I can clearly attest that I in no way argue against the validity of archetypes (insofar as they are defined within the fields of psychology and mythic literature that really lob them into mainstream usage) nor would I ever dare to question the profound sacredness of Nature.
This all seems to boil down to the subject of a scarcity model (as frequently discussed in the polyamorous communities and literature), in this instance a “scarcity of identification” or a “scarcity of devotion”, or a “scarcity of spiritual cohesion”, as if somehow the existence of different lenses of engagement (e.g. Theistic, Naturalistic, Humanistic) somehow cancel one another out. Any well adjusted polyamorous person (and any solidly engaged devotional polytheist) can attest to the fact that “more” does not in any way equate to “less” or “spread thinner in some areas”. More means more. (Polyamory doesn’t demand that one engage with all partners the same way, or hazard that all relationships should look a certain way, or smell a certain way, or sound a certain way. Similarly, Polytheism doesn’t suggest that all deity relationships must look a certain way or smell a certain way or be flavored and scented and structured in the same fashion.)
More equals more. That’s kind of how math works.