Talk animation

Hi,

I’m working on NPCs for a game right now which will be then imported into the UE4 later on.
For rigging I use auto rig pro.

My question is how can I blend a talk animation with an idle or walk animation ?
Do I need to separate the head from the body to accomplish that ?
At the moment I’m only using joints for facial expression (btw I have no idea of how to get rid of the artifacts in the face…)

The characters should be able to talk when some events happen. (Pressing a button for example)

I already tried to separate the head from the body, but animating them synchronously is a pure nightmare. I tried to adjust the weights and all but this doesn’t work…

For anyone having issues with the vertex normals , this tutorial helped me a lot to get a more smoother transition from head to body like in the second picture:

But when it comes to animating everything falls apart…