I agree with you that a B/B Val'kyr will haunt first before an H/H Val'kyr and probably gain an advantage. However, for the most part I plan to use my Val'kyr in PvE such as the Celestial Tournament where I most likely will need to drag out the battles, or where I will probably need some of my pets ...

I've been searching for the unborn val'kyr for a long time, and while I have been able find some, I have never encountered and H/H breed. Any quality is fine. Please let me know how I can compensate you for your time. My battletag is Recon#1385.