blender FBX animation vs nla-strip - All possible object-animation combinations in Unity

I have a few objects, each with their own animation.

Importing in Unity seems to multiply these into each possible combination, most of them silly (don't want the animation for my 2nd object on the first). I could manually remove the unwanted ones by removing them with the "-" in Unity, but not sure how good an idea that is (especially when updating that FBX a lot).


Now if in Blender we select each object and then in the animation "Push Down" to an NLA-strip and then export (with adjusted export-settings to NLA-strips), then it looks much better, 5 unique animations (one for each object) just like I'd expect.
Thing is, I'm not sure what the differences are between the "normal" animation and NLA-strips... or why Unity would even treat them differently. Any disadvantage of NLA-strips, or any way to get it to not show all possible combinations without?