Often each change makes little difference and many small changes are needed.
You could use a single Skeleton and AnimationState for multiple on screen elements. Apply the AnimationState to pose the skeleton, then position the skeleton and render it for each element. All of the elements will have the same pose, of course. To cut the work needed to pose the skeleton in half, pose the skeleton only every other frame. That is what the text you quoted is talking about.
Check how many draw calls you are using per frame. If that is your bottleneck, using less CPU by posing less often or having fewer bones, mesh vertices, keys, etc won't help much. Set totalRenderCalls to zero at the start of a frame and print it after rendering (and after ending the batch). If you can fit all your texture regions on a single texture atlas page, you can render the whole screen in a single draw call. If you can't, try to organize them to minimize draw calls. If you can't do that either, there are ways to improve it, if they meet your requirements (GLES3.0, etc).
