If I am a Sacred Huntsmaster Inquisitor, I gain Animal Companion (Ex), the regular animal companion class ability.
As an Inquisitor I have a Domain so the Domain I choose is Scalykind Domain, specifically the Saurian Subdomain, which gives me Dinosaur Companion (Ex):
"At 4th level, you gain the service of a loyal animal companion. Your effective druid level for this animal companion is equal to your cleric level – 2. You may only choose a dinosaur as your companion."
So do I now have a pet at my level, and a pet at my level -2? I assume you cannot use Boon Companion RAW because this isn't the animal companion class feature but a 'dinosaur companion', and the feat specifies animal companions. Scalykind core also has a "Serpent Companion (Ex)" which is basically the same but its a weaker snake instead of a dinosaur.
Alternatively, if I took the Animal Domain instead of Saurian, it gives me the Animal Companion (Ex) class feature. Do multiple sources of the same named class ability stack? Or can you only have "Animal Companion (Ex)" for one single source? If I can have Animal Companion twice, one at my level and one at -4, can I use Boon Companion on it to bring them both up to my level?