The solution has an odd spot when creating the pvcs. It is much safer to create first the drupal pv / pvc and then the mysql pv / pvc (or vice versa, but as a combination). If you first create both pvs and then both pvcs as shown in the solution video, it is completely random which pvc is bound to which pv, since both pvcs can be bound to both pvs. You get a 50% chance to have a right or wrong setup (it happend to me 
).
For the game of pods, this might seem irrelevant. However in real live, having the mysql data in the /drupal-data directory and the drupal data in the /drupal-mysql-data might end up in data loss and tears.
I think it is a good lesson to show, that the order of creating things might be important. So please don’t fix this by changing the scenario pvs capacity / pvcs requests so that they are unique. Instead point it out explicitly in the solution video that the order of execution is important!