For most if not all radar controllers, using the drag and vector feature is the only way that they send heading and/or altitude commands. Did you know though that you can send those commands from the flight strips, in the aircraft’s individual menu?
It is good practice to practice sending commands using the latter method of the flight strips to send heading and altitude instructions for special circumstances. Such as vectoring flight of XX flights, aircraft that are on top of or close to each other.
When aircraft are in close proximity to each other it will be difficult to reliably click on the correct aircraft. By using the flight strips it removes any doubt as to who you are sending the command to.