Separating animations from FBX makes smaller files?

I have some character models with embedded animations in FBX made in Maya 2015. After some experiments, I found that by extracting the animation in Unity 5.6.1 (CTRL-D), then re-exporting the FBX without animations, the resulting model + animation results in a MUCH smaller combined file sizes than the single file. As far as I can tell, everything seems to be functioning as normal.

Does anybody know if there's any drawback to this method to save space on my project/build? or have any insights on why there's such a difference in the file sizes?