Question on when to use Social Stigma vs Odious Racial Habit on Monster Races

[phayman53]

I am either misunderstanding a nuance or have noticed a somewhat inconsistent use of racial disadvantages between racial templates in supplements. Some monster races have Social Stigma (Monster) [-15] and others have Odious Racial Habit (Eats Other Sapients). Basic Set says that large, dangerous predators should have Social Stigma (Monster), such as vampires and bears. But this seems to be because they eat sapient beings, so Social Stigma (Monster) and Odious Racial Habit (Eats other Sapients) seem to cover a lot of the same ground. What is the difference and should they ever be used together?

For instance, should a race of Tolkien-like orcs have Social Stigma (Monster) or Odious Racial Habit (Eats other Sapients)? Or should they have both--or maybe Social Stigma (Barbarian) and Odious Racial Habit (Eats other Sapients)?