Hello,
Not a silly question at all.
These are the ICAO Standard Procedures. however, the Commander has obviously the liberty to alter these procedures as in his/her opinion another course of action is better for the Flight Safety.
What to do in which case is not so easy to tell here in front of a computer...It comes with experience and airmanship. there are so many variables to count with, and that is why we as Flightcrew deserve respect, a good salary and a stressfree life...