This is one of the chapters that dates itself by what it assumes, and it is worth reading as a document of its own circumstances rather than only as a maxim.
The picture behind it is of competing territorial states with standing armies, frontier zones under permanent military management, and cavalry as a strategic arm requiring years of breeding. That is the world of the later Warring States, and the same world produced the extensive military and administrative literature that the book argues against in chapters twenty-nine, thirty, thirty-one and fifty-seven.
Read in that setting the chapter is not making a general observation about greed. It is objecting to a specific policy, the standing conversion of agricultural capacity into military capacity, and it is doing so on grounds a ruler would recognise: the horses are the same horses and the fields still have to be manured.
The book's political chapters are consistently of this kind. They do not appeal to the welfare of the people as a moral claim so much as observe what a policy costs the state that pursues it. Chapter thirty counts the bad harvest after a campaign. Chapter fifty-seven counts the thieves produced by an excess of laws. Chapter seventy-five counts the hunger produced by taxation and treats the resulting disorder as the ruler's own work.
The frequency of such chapters is one reason the text was read as statecraft in the centuries immediately after it was compiled, and it is the strongest evidence that whoever assembled it expected to be read at court.