It's reasonable to assume they have different levels of sentience/intellect, considering how they are mutant experiments made with a variety of different alien species. At least, they are more like dogs. They have instincts and feelings but the collar allows for complicated orders. There is a reason all characters speak to them as pets. For an example, notice how the girls compliment the manticore directly when they do good in battle, not the one ordering them.
What I'm trying to say is, the collar does not give the controller some kind of VR perfect control of the wearer, its more like a mental link that allows the controller to communicate directly with the creature and tell them what to do. Pretty sure if the creature truly hated it's master, they wouldn't obey.
Also, they are not wearing the collar in all Pandora scenes, further proving my point.