ffmpeg: How to overlay two gifs to play at once?

[Mugunga]

I have a background .png and then two animated gifs I want to play at the same time. However, currently I can only get it play the gifs sequentially, so one gif plays in entirety while the other gif is stuck on the first frame, then the second gif plays while the other gif is stuck. They should play at the same time.

Also, if one gif is 3 frames, and another is 6 frames, how can I make the first gif repeat twice for one cycle of the second gif?

Current Command:

ffmpeg  -i background.png 
-i "smoking_cigarette.gif"  
-i "spinning_hat.gif"  
-filter_complex "[0][1]overlay=format=auto[i1];[i1][2]overlay=format=auto,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse=dither=bayer: bayer_scale=5,scale=400:-1:flags=neighbor " 
-loop 0 final_gif.gif

[pandy]

Command (filter) 'movie' can be useful in such cases: https://ffmpeg.org/ffmpeg-filters.html#movie-1