According to the company law, holding more than 67% of the shares essentially has an absolute controlling right, the majority shareholder can make decisions on any matter. If you hold only 51% of the shares, you only have a relative controlling interest, and you have to have 2/3 of the votes to pass major matters, then you can make a choice at this point.
As you this is a small company, you can not have a board of directors, only executive director, each other served. But the corresponding major matters to the shareholders' meeting decision-making, to ensure that they can control the company to a certain extent.