They don't really strike me as finesse hunters, so maybe drop Weapon Finesse and boost Str to 15? That would be the normal Str for downsizing Arctognathus to Small.
Drop the Climb speed, drop the natural armor from +4 to +2 (dinocanisauruses were explicitly armor-plated). Mention that, although they take small prey singly, they work together to fell larger animals in their flavor-text.