These are good observations. However, I think you are inferring plot points from what is merely literary technique. H&C using the same disguise is well explained by EY intending us to identify Hermione’s manipulator with Zabini’s. Similarly, the many attempts/Hermione’s exhaustion are well explained if EY wants to make it clear what the nature of the attack is without spelling it out explicitly.
These are good observations. However, I think you are inferring plot points from what is merely literary technique. H&C using the same disguise is well explained by EY intending us to identify Hermione’s manipulator with Zabini’s. Similarly, the many attempts/Hermione’s exhaustion are well explained if EY wants to make it clear what the nature of the attack is without spelling it out explicitly.