This is already what Natives do; they research five different things in each of the three branches, then reform their government when they come in contact with the Old World. The exceptions here are the Andean natives (stuff like the Inca) and maybe Mesoamerica (Haven't played a Mesoamerican native); the OPM Natives in South America and all of North America's Natives operate on the aforementioned flowchart.
You're right there is some flavor built in here but just firing up a new game as Aztec you'll notice the techs being researched are Feudal Monarchy, The Barque and Eastern Swarm.