Well you better let guys like James Madison and a dozen other signers of the Constitution know of your opinion since they voted and approved an identical bill to the 1787 Ordinance during the very 1st Congress under the Constitution in 1789.
I don't know what you see in Article IV. I see it gave Congress exclusive control over the Territories including the power to prohibit slavery if they so desired.
Here is a discussion of the constitutionality of the Northwest Ordinance that holds that the Ordinance is not constitutional. Link.
lg, in response to your post above I checked my archive of old posts and didn't find much about a previous discussion on the NWO that I had been involved in, but I had archived the text of the above link on my computer.