Cards are said to be in every living/sentient being (that includes robots and plant). Now, assuming this applies to humans too, when we look at all cards, there's no simple human card.
Look at Frostlings. They have 2 different cards, even if they are one species. This means that cards are "essence" of the individual being. Frostlings have two professions: Scoundrels and Rogues. So the card that drops from a being depends on what it did in it's life. Most of monsters drop single cards per species, because they are very primitive. E.g. Rabby is just a Rabby, it can't be Guardian Rabby or Gardener Rabby, right? So, if human cards are to exist, we wouldn't get a single one from humans. We would get a Human Collector card, Human Carpenter card, Human Blacksmith card etc. They would grant us abilities of the person they were formed from.
That's actually a very interesting chain of thought - one that I didn't think of. It would be interesting if Zhamla actually hunted down the strongest Collectors to collect the Human Collector card.
What I'm wondering about, though, is what's with all the fire? When we meet Zhamla, he doesn't seem to mage-type. Even as a kid he was training with a sword. And as a grown-up he sliced the Thorn Worm with his blade. So why is everything burning where he appears? All the reports we find tell about fire and smoke. Was he riding a dragon or something? Slan'kerz? Well, that certainly would explain, why he would be guarding his sword. Can't wait for more plot content.
Edit: On second thought, if he was riding a dragon, the Flying Fortress wouldn't have been safe from him. So either he wasn't, or he didn't know of its existence.