I took an entirely different track as New Spain. The campagin objectives are elminate the Maya and Aztecs. This in mnid I decided not to ever ally with either for any reason. I decided to think like Hernan Cortez. Ally with the Aztec's neighbours lend my guns and steel where needed and let the natives kill each other. Worked well. The Tlaxcallans, Tarasans, and Chichimecs all welcomed by friendship and gold. And it became very appearant that for all their apperance of force the Aztecs are a paper tiger. They had serious trouble dealing with the Tlaxcallans (who start with 1 city, who grap their rebel neighbour to the south in the first 5 turns). And the Aztecs lost ground to the Chichimecs and Tarasans in the north. Add to this that paid off with trade rights and map info the Aztecs will leave you alone till you start something leaves you fit and ready to deal with your real threats. New France and the Maya. The Maya are as agro as the Tlaxcallans and you are in their way. I've had trouble keeping them off my arse and lost a settlment to them. New France shows up in Florida. I was trying to get a NA foot hold and got fed a plate full of my buttocks with all the trimmings by New France. Kicked my out of Florida and Promtly named the village I was holding Fort Caroline.

Militarily New Spain is flat footed till your Viceroy is at least a Viscount. By then you can build a full tech Minor city. Your stuck with Pike and Sword militia. Plus dismoutned conquistadores at large town level. Guns come with either Count or Marquis (I haven't goten that far yet).