I've only played a few partial games with the Sanguine Pact, but it seems that though Vampire strength scales with technology changes, Vampires fall way behind once you unlock Nationalism and the ability to create Corps. Since they can't be permanently killed, they still can be useful to an extent, but as technology improves they fall farther and farther behind, to the point where they can be one-shot by city defenses. And once you unlock Armies, Vampires are downright useless as combat units.
I guess it makes some sense that individual vampires can't take down large groups of modern troops... but since the early game goes by very quickly, and since you may not get your first Vampire until pretty far into the game if you're unlucky with barbarian camps, Vampires have an awfully short window of relevance.
I guess it makes some sense that individual vampires can't take down large groups of modern troops... but since the early game goes by very quickly, and since you may not get your first Vampire until pretty far into the game if you're unlucky with barbarian camps, Vampires have an awfully short window of relevance.