One person can be secretary, treasurer,and chairperson at the same time and this could happen in strata schemes when no one wants to be in the committee or in very small schemes. Of course if there are 3 or more committee members then it would be better that the roles are split. My experience is that when one person holds multiple roles it’s to control everything.
If 25% of owners request a general meeting then one must be called. This might be a way around for the significant number of owners not having been notified of the AGM. Of course the same owners will once again not be notified if the reasons for the previous failure is not fixed. I believe 21 days is needed for notice by mail and 14 days for notice by email.