Can you technically combine multiple mocaps from multiple sources and create a new single entity that's unique from the other two, like an alien animation or something?
TL;DRLayering animations from different sources would likely look broken and be uncontrollable, though combining distinct halves, such as a mechanical lower body with an organic upper body, could work.
Well, you could certainly load an animation on one layer and then create a second layer and load a different animated result onto that. But what you end up getting, actually, is a bit of a mess. I don't think you would get something that looks like a believable alien. And it would just look completely broken. And the problem there is that you're then unable to control the outcome of the hundreds of animations that come off of that. So could you have a happy accident and go, wow, I hadn't thought about that, and then start to plan out how you would create that later on? Maybe, but I would assume it would end up being more of a technical mess. If you're talking about something, let's say you have an alien where the bottom half is mechanical and the top half is organic, and there's an actual disconnect between those two, you could certainly do something like this. But what you're doing is you're combining the top half of something with the bottom half of something else. You're not actually meshing the two of them together and just sort of going, I got red, green, blue, purple, plop it down, and then you end up getting brown.