i also disagree with this idea:
Exotic plants dead bodies don't work into this system either, their leaves etc. They create a different microbe environment that is not conducive to what the natives need.
rotting organic matter is rotting organic matter, i dont think the native plants will turn their nose up at non native plants rotting organic matter. and i dont think the indigenous microorganisms are harmed by non native plant matter decaying.
the IMO (indigenous microorganisms) will be around in the soil, and if you build and environment they like with decaying organic matter (which could come from native plants, naturalized feral plants aka "exotic" and highly cultivated plants alike) they will come and expand. you might enjoy looking into natural farming's methods of cultivating IMO. the simplest of which is to get some soil from different fertile spots and to grow the IMO gathered in a medium, then add it to your soil.
this is actually pretty complicated stuff, i dont think many people have a grip on the particulars exactly, even someone who makes a case that sounds logical. just how do they know about all the particulars that are happening in the soil? how really can they tell, that non native plant matter decaying is causing some problems for the native plants. this statement doesnt make sense to me and seems to be more about a native plant enthusiast bias than the fact. i suppose my bias tells me something different, the more different kinds of rotting stuff you have the better, including non native plants/tree leaves, etc. i really cant say for sure i know what exactly is happening deep in the soil, but thats what my experience tells me and it works, and that whether a plant is native or not doesnt matter to the soil.
i do like that website for their information pages, but i still disagree with most of what they are saying in that particular article.
and hey you may throw whatever i am saying out the window, thats fine, i can just say what i think, and what experience tells me.
i say plants TONS of stuff, mix in natives with feral naturalized plants, let your desireable volunteers grow where they will, add in good cultivars as you see fit. sure theres some rhyme and reason to putting certain things together, but i think you cant get too rigid about it ONLY being this plant with this other plant, its much more open and free flowing than all that.
i am also not a native plant ONLY type gardener, and i tend to think people on this wave get some funny ideas that i dont think are entirely accurate. plants want to grow anywhere they can, and they are good at it =). and native plants are particularly good at growing in their native region, this is true, but i dont think its also true to say they couldnt adapt to another locale/ soil conditions/water amounts and do great as well.
i am also fond of both naturalized "exotics" that can grow prolifically with very little inputs (another words- all feral plants whether strictly native or not) and cultivars, at least good, non fussy, tough cultivars. things like lemon balm, chicory and plantain are common naturalized NON NATIVE plants that grow as well as natives and are very non picky about soil type, mycorrhizal connections, while also being medicinals/edibles that can keep on even in adverse conditions. plantain is so foreign that the native peoples called it "white man's foot" which is pretty clever since it does look very
footprint like, and used it to track white people's movements during the early settlement. all of these are welcome in my gardens =)
the beauty of native plants and naturalized feral plants is that they are so prolific that its hard to kill them even if you wanted to! so i dont think some of the other things you are stating are accurate IMO, like you have to be really particular and careful about not putting them in the wrong soil type, and only native plant matter/leaves can support IMO and proper mycorrhizal connections, or that they have to be isolated in native only groupings.