[Taqwus]

Some of the Mictlan sacreds are also capital-only, right? That might cause problems in a map of decent size, or a fairly slow game.
If they survive to build up enough of a blood machine for summons (cross-breeding for bulk fodder, say) than it might be less of an issue, but then there's not many units left to bless (other than angelic types), with sacred non-Void summons being rather rare.