In Chapter 9 of Seabiscuit, can someone please explain why Tom Smith is trading out Seabiscuit and his twin, Grog?

If we look at Chapter Nine carefully, we can see that Tom
Smith had a very low opinion of reporters, whom he thought to be "parasitic." In
response to the increased press attention that Seabiscuit began to receive in Chapter
Nine, we are told that Smith "elevated obstruction to an art form." One of the
strategies that he used to do this was to pass off Grog as Seabiscuit, because their
near-identical status meant that the reporters, most of whom knew little about horses,
had no chance of discerning the difference between them. Such strategies were carried
out for three reasons:

1) Such disguises meant that
Seabiscuit's form was concealed from the reporters.

2)
Exercising the horse in private without the reporters watching helped Seabiscuit remain
in form and not put on weight.

3) Lastly, such a trick
enabled Tom Smith to gain "sadistic pleasure" in fooliing the
press.