Make provision both in your Shareholders Agreement and your MOI for any significant shareholder (one who holds 10% or more of the issued shares in any class of shares) to call a meeting of shareholders for any purposes under the South African Companies Act.
That way if you end up with only two significant shareholders either of them can call a meeting and not fall foul of the provisions of Sec 65(3) of the Companies Act which provides that any two shareholders can request (requisition) a meeting of shareholders.