Your major problem is Alex MacGillivray, and your PoD is too late to get around him
Little Alex was the Creek chieftain who negotiated a treaty with Washington and Knox that basically made the Creek a state (with poorly defined borders, but basically modern day Alabama). Unfortunately, Alex was a Tory - his father fought for the British during the Revolution, he was intriguing with the Spanish before the ink was dry, and he never referred to the American government as anything but "the rebels". He seemed to believe that the British, Spanish, Heaven itself or some combination of the above would crush the Americans any day now. Unfortunately, Alex's example entrenched the idea in the War department that honest negotiations with the 5 tribes were - not in the cards.
I can imagine some sort of larger, fairer reservation scheme than OTL being implemented early, but the key problem is that the US government doesn't trust the 5 tribes to nominate their own leaders and spokesmen - because they tried that, and it didn't work out well for America.