ACC - Joe Brock owns 10,000 of the 60,000 outstanding shares of Big Corporation

Joe Brock owns 10,000 of the 60,000 outstanding shares of Big Corporation; Leslie Ross own 20,000 shares; Mark Jones and his twin brother Sam each own 5,000 shares; and about 300 other shareholders own the remaining 20,000 shares—with no one other shareholder owning more than 1,000 shares. According to the provisions of SFAS 94, since Leslie owns half of the outstanding shares, he, in general, “controls” Big Corporation and, thus, should consolidate his interest with that of the corporation. However, Joe Brock is unhappy with Mark’s management decisions and plans to “challenge” his authority. What factors arise in considering if a minority investor can maintain such control or even prevent others from exercising such control?