One of the struggles that developers face when moving to Drupal 8 is the lack of best practices in deploying Drupal sites. The Challenges in deployment- Dependency Management, Drupal Contrib Modules/Themes, Configuration Management and of course Code Base. Drupal 7 has no such problems. Ahhh, Drupal 8 comes with lots of stuff to manage. One of the biggest change in Drupal 8 is the adoption of Composer. Good things come at a price.
We will use one codebase for one Drupal site and use git for version control and deployment.