Did you noticed.......

[Taqwus]

HJ -- A big difference is that blood is far less tied to magical sites than the rest; at least in Dom I, anyway, even the Damned Merchant (blood 1?, gives 1 slave/turn) was pretty rare. Hence you can't just conquer a province somebody else searched and get free slaves, normally. Nor can you find the sites with a handful of mages searching or casting divination spells, and reap blood income for free (i.e. no further action); your blood income is heavily tied to population and blood mages (since SDRs won't help as much). It's harder to get started, but it used to be easier to boost your capacity once you did get started so long as you had heavily populated provinces.