I highly doubt that this will work, unless the replacer does not depend on the original race's .esp file.
Of course it's possible to remedy this with some FormID exporting / importing and other bash magic, but it would require some work on your part.
Thanks. No, it replaces Slof's Playable Xivilai.esp with a new Slof's Playable Xivilai.esp, simply changing the Xivilai creature to use Slof's resources. So it doesn't depend on another master. I'm mostly worried about messing something up as I'm a bit wary of having different race mods. Here's the description:
"MADC AT'S OOO BADDIE REPLACER EDITION: Now replaces all creature spawns, summons, and the two named Xivs in Camoran's Paradise with Slof's Xiv Race NPCs! For use only with Oscuro's Oblivion Overhaul, V1.32 or higher."
EDIT: http://arkngt.googlepages.com/slofs_xivilai_summon.jpg with the summons at least.