The SM/ASM relationship depends on the show, the
theatre and it's traditions, and the two people filling those roles.
The last show I worked on had 2 ASMs (I was one), and the
stage manager had me do all of the sweeping/mopping/cleaning of
props and the other do all of her coffee/food running, and we both handled
props and costumes and actors backstage. She kept
track of all of the director's requests and changes and called the show from the booth, and yelled when someone needed to yell. All in all, our
role was much more active and interactive, and she did her job from an audience seat and the booth.
However, while this was her style, I'm
stage manager now and there has been no objection to me taking a more active
role in the setting up process or directing from the
ground with my ASM helping instead of slaving away alone, though when it comes to show time I still sit up in the booth with the board ops and
call cues to my ASM backstage.
The last theater I worked with had the
stage manager backstage calling cues and in between them working harder than anyone to get
props and actors,
etc. prepared to go on. There are a alot of things that
effect the relationship. Take your own route as a
stage manager within the bounds of your
theatre's setup, and decide whether you want a slave (which you could prpbably get) or a helpful
understudy.