So far I have found the concept of pre-requisites difficult to implement in an automated fashion.
It is easy to automate the process of determining that at activity is complete (e.g. a quiz).
It is easy enough to determine if a course is complete (e.g. all activities complete, or grade achieved).
However, the core and plugins for making one course dependent on the completion of another allow you to start course 2 while course 1 is incomplete, but not complete course 2 until course 1 is complete. Another plugin automatically enrols you in course 2 when you complete course 1, but that is not useful if not everyone doing course 1 should go on to course 2.
With regard to face recognition, Moodle allows for many login authentication integrations with third party tools (see https://docs.moodle.org/36/en/Authentication). There may be a way to integrate face recognition with one of these external methods.