The original discussion was about relative change to salary, of which there has been little to no change seen amongst the CEOs in question. How much the salary is in absolute figures really means nothing with respect to discussion.
Now, total compensation is quite variable as it is largely dependent on stock price. While a good CEO theoretically can compel the price of stock higher by building a better business, realistically it is outside of control of the company.
Has it? Sources indicate that the CEO of Ford's salary has remained quite steady at $1.7 million.
Perhaps you are confusing salary with total compensation?