Yes you can splice them together if you want. I mentioned that Yamato did a couple of versions of her and different head. Just look at the freestuff at his site.

You can Frankenstien most figures heads to most figures bodies. Many of us do it it all the time. It's the uv's that don't match so you get a texture seam where you splice the two necks. Thats why Judy and V3 were a good match, they use the same textures.