Yeah sure, but it's faster to store those in VRAM. If VRAM is to small, the system will load it from the regular RAM of course, which could be laggy.
This is only solution I found how to import complicated animations with good framerate with minimum quality lost and maximum optimisation
If importet boneanimations don't run as smooth as larger frame-by-frame clips, personally I think your problems are elswhere. Did you preload the animation sprites in the layout (like they exist ofscreen while starting the layout or something). Creating huge, non preloaded objects right before the animation starts surely could cause lag.
But listen - if it works for your use case the way you are currently doing it, thats's totally fine. If you run into any performance/memory problems with that, you should reconsider your conclusions. But most importantly - go on with it and see what works and waht doesn't.