Many of the parkour skills are presented as multiple skills in a set, e.g., Safety Tap – Safety Rolls – Dive Roll. This is because you need to build strength and/or skills to be able to progress to the following skill in that same set.
Although the sets are also given in a somewhat progressive order, you don’t necessarily have to be able to do the final skill in one set to be able to move onto the next, e.g., knowing how to dive roll is not a pre-requisite for being able to hurdle. Use your best judgement.
Note: Knowing how to safety roll is very important for safety in training. It should be mastered before moving on to other skills.