[Dragonlance/Faerun] Anyone here met any Cataclysm/Wall of the Faithless defenders?

[PairO'Dice Lost]

Well, maybe. It's much more a fairy tale than any attempt to be realistic or historic, and the clash is really between law and chaos, with the Empire and Saracens being pawns of the two sides. I picture "historic fantasy" as something a little more grounded in reality. "Reality but with magic."

From what I remember of the book I would agree. Certainly not historical fantasy as I’m familiar with it.

The historical fantasy genre is about how closely the peoples, cultures, and other trappings correspond to those of a particular real historical period, the involvement of iconic historic or mythic figures in fantastic events or the introduction of fantasy elements to historic events, and so on, not about power levels or grittiness or the like.

Gaslamp fantasy and wuxia are considered sub-genres of historical fantasy, and both vary widely in degree of grounded-ness. The former includes lots of less-grounded works like the Temeraire series (dragons everywhere!), the Shades of Magic series (multiple alternate Londons with more magic than ours!), and Jonathan Strange & Mr. Norrel (adventures in Faerie and worlds beyond!)--the latter of which has much the same fairy tale feel that Three Hearts and Three Lions does--and the important part is that they're all set in a reasonable facsimile of Victorian-ish era England. The latter includes a ton of stories involving greater or lesser amounts of magical martial arts, the most famous being Romance of the Three Kingdoms, and the important part is that they're all set in a reasonable facsimile of ancient China.

Meanwhile, a story being a "fairy tale" is fairly fuzzy from a scholarly perspective (just to start with, there's lots of debate as to whether a story can be considered a fairy tale if it's not authentic folklore even if it otherwise meets all the relevant criteria) but in general it has much more to do with plot elements (archetypal characters, often defined by their role more than their individual existence; repetition in the narrative, especially things coming in threes; "just-so" plot points and setting elements that "just happen," lacking explanation in the story; clear moral lessons at the end, whether explicit or implicit; and so on) than about setting. Indeed, the magical realism genre is basically the fairy tale genre with the traditional historical or fantastic setting swapped out for a contemporary one.

Personally, I could see characterizing Three Hearts and Three Lions as both a historical fantasy and a fairy tale, but D&D only really borrowed the historical fantasy elements and eschewed the fairy tale ones.