Moodle enables students to view resources and complete the activities in any order. For the period the resources and activities are available to the student, the student can access them at any time and in any order. A paragraph from https://moodle.com/ explains its approach towards e-learning:
The word Moodle was originally an acronym for Modular Object-Oriented Dynamic Learning Environment, which is mostly useful to programmers and education theorists. It's also a verb that describes the process of lazily meandering through something, doing things as it occurs, an enjoyable tinkering that often leads to insight and creativity. As such it applies both to the way Moodle was developed, and to the way a student or teacher might approach studying or teaching an online course.
For our purposes, it's really best to look at the object-oriented approach of Moodle in an instructional sense. If one of your quizzes is not working well, just replace it. You don't have to rewrite...