Two different things going on here:
The SAA for the meeting (arrives early, sets out the chairs, bangs the gavel to start the meeting....) is a MEETING ROLE used in the agenda and is already assignable in the Umhlanga Club.
The Club SAA (makes sure that you don't run out of voting slips... etc) is a CLUB OFFICER elected annually or every six months.
In some clubs the Club SAA always performs the meeting tasks - and the way you manage that on easy-Speak is to assign the same person to the role each meeting. But it does not have to be that way and you may assign anyone to the job.
The same logic applies to 'President's announcements' or 'VPE's minute' - normally the club officer stands up to complete the task but in their absence someone else would stand in for them.