When friends and I play RPGs (pen and paper; occasionally D&D, but mostly Champions/Fantasy Hero), occasionally new races become available. One of my friends, if he sees that race being particularly strong, likes to ask the question, "why doesn't that race rule the world". While I think he doesn't sufficiently take into account demographic/sociologic questions in that analysis, it's a useful tool.
And looking at Abé's drákon, it becomes a particularly relevant question. After all, the drákon have all the advantages of humans (tool use, communication, coordination) with a number of advantages all their own. They almost never get sick, they don't harbor vermin, they're stronger than a hundred men (in fact, they were stronger than the strongest weapons men had at that time), they have senses hundreds of times as sensitive as a human's (with none of the problems that would be caused by such sensitivity), they're exceptionally attractive (particularly useful if you want to take over by marriage), they're at least as intelligent as humans, and they never fight among themselves. Oh, and they can turn into either smoke or dragons. And occasionally they get other Gifts, as well.
A minor detail from a personal perspective, but important when analyzing the race: they also breed at about the same rate as humans.
When looking at all that, their life expectancy back in the 18th century would be significantly longer than a human's. In fact, possibly considerably longer, because there's no signs of infant mortality being an issue among them, and that was far and away the biggest detractor from lifespan back them.
Really, there isn't a single reason that they wouldn't take over the world (or at least as much of it as they were interested in).
Yes, they can be kept in human shape when blindfolded (or kept in total darkness), but with that kind of strength, good luck keeping them blindfolded. You can chain them up, but they're apparently strong enough to snap those chains with a stray thought, so who cares?