Strata Committee Positions

Hello, I’m in NSW and on 2 harmonious Strata Committees (SC). Im active in both liasing and participating with owners, tenants, contractors etc to reassure some. 

My question is at one property (18 lots) we elect SC and fill positions of chairman, secretary and treasurer but at the other (9 lots) we only elect SC members but not the positions. Should we be filling positions? 

Thank you in advance. I’m addicted to this community (forum).