I was just thinking that even though it would take a lot more design and maybe even more programing to make a worthwhile challenge to get it, but:

What if you could splice your race?

.......Hm. A Vygoid with a Sillixx head would be weird...An interesting idea though! Hybrids could have smaller bonuses, but more than one. You could have like a max of three species spliced. I would totally be a Vygoid, Sillixx, Inergon hybrid. That would be epic.

yes, interesting idea.