Tall is still viable, some civilizations have more advantages in going tall (like Kongo), but in general its possible for any civ. Tall requires much more space for cities to support high housing and good spots. If I go tall, I place cities 4,5 or even 6 tiles away from each other (if in safe), then rush commertial districts for trade routes, feudalism for effective builders/farms bonus and industrialization for factories overlapping bonus. 4 cities is optimal in terms of amenities, but you can place more. Regarding governments, I try to rush Merchant republic - +2 trade routes is so good as you are limited in trade routes number.