I've noticed the same, with other monsters as much as vampires. They share one or two common traits between worlds but are otherwise distinct. Only pagan gods and humans seem largely the same between realities.

[Is that because humans already differ so greatly in personality? He can't guess at the motivation for tinkering with the nature of monsters but not of humanity, whether their creation here is his Father's work or another's. Maybe they're just the universal favourite.

He gives Alucard an appraising look. There are differences right in front of him, too.]

There is no such thing as a half-vampire in my world. They also have more fangs.

[He gives a slight shrug of his own. Not hard to come to an agreement on that particular issue, he thinks.]

Easy to come to a consensus on so uncontroversial a topic. Have you ever met anyone who'd prefer confinement to freedom? Thorne's own Summoned don't care for the place, from what I've seen.

[Michael absorbs the information about the Free Cities with a nod. He has few friends there, but he'd assumed as much. Even Solvunn expects its Summoned to work in exchange for what's given.]

That does sound like the modern world. Solvunn gives freely, but always with the expectation of receiving something in return.