If you can find it in the Writing Club, I wrote a fanfic titled "Southward the Tigers," whose action takes place within the lifetimes of King Frank and Queen Helen. A major element in my novel was a possible origin for the Calormenes.
As a student of Russian and Soviet history, I discovered that in the real world, in or near Kazakhstan, there was a Turkish-related Islamic tribe called..... the KALOR. Mister Lewis almost certainly knew of their existence, and MIGHT have derived the name "Calormen" from them. So my story imagined Tash transporting a clan of Kalor to the Narnian world.
In such a case, whatever became of their theology once transplanted, the Calormenes would have arrived speaking ,an Islamic language, and observing Islamic customs. This in turn would have affected how they spoke about Aslan.
