If you really use orientation, then you are doing it wrong. Only rotation should be animated. You may want to read up on that old Quarternion vs. Euler thing and what generally best practices for 3D rigging are, not just in AE. This is a common thing even in 3D programs and on complex rigs will also entail using Nulls and parenting to neutrlize and decouple individual rotation axes to prevent gimbal lock. Again, you need to study up on this on a broader basis.