What's the process for animating two characters together?

[pickersZ]

@MostHost_LA

You literally have no assurance that A will be at A and B will be at the correct position/orientation unless you animate a bone or some other sort of reference point (socket) in the same location.

The reliable way is a bone.
The semi-reliable way is an arrow component in BP to signal placement (common for interactive things that have no skeletal mesh).

And less than reliable way is hard coing a location…

For a scene with two or more characters animating together, it would have to be precise at a specific location and rotation. It cant be a dynamic situation where the the characters are constantly moving.

As long as there is no physic / hit collision considerations, this is the most suitable for animating groups of characters in the scene.