[Baalz]

Oh, I think you've got a pretty good chance actually. The other blood nations all have other research that they need early. Mictlan for instance won't start blood hunting until after they hit constr-4, then when they do start blood hunting the first several turns the blood slaves are going into sanuine rods. Lanka probably really wants some alt research early on and probably construction as well. Either of them may very well also go for early site searching spells because they're pretty unlikely to have a rainbow pretender. Aby, on the other hand if configured how I suggest goes up to evo-2 then nothing but blood. Obviously its not a guarantee that you'll snag the uniques, but I think its a very rare situation where you don't get some of them, and I think it'd be more common than you think to get most of them - particularly as those bless nations again have a high chance of having a pretender who is not set up to help with the summoning so have to empower or forge several other boosters. As you mention, your final fallback is the vamp lords - who give you the diversity into death that is really most important anyway.