Not sure if exclusive is the right word, but similar to say skin color or ear genes, you can select multiple types in the xenotype editor, and then there is an equal chance of only 1 of them being active on a pawn.

For the blood here though, it seems like all selected blood genes are active simultaneously. How does that work exactly, and it would be great if there was an option to change that behavior to be like with skin color, ears or other exclusive genes.