The Phylakes Daoi’ loyalty is unquestionable and their ferocity unmatched, acting as a nucleus for the royal cavalry.
The strong ties developed between royalty and the Ktistai priesthood made these zealots the perfect recruitement basin for the king's guards. The beltistai's loyalty is unquestionable and their ferocity unmatched.
Historically, the numbers of these guards would have been greater than presented in-game, thus acting as a nucleus for the royal cavalry. The ktistai were so close to the king, that the succesor would either be chosen from their ranks, or become pontifex maximus of the priesthood. The ones recruited for the Beltistai corps must have been trained from infancy, while the secretive nature of their order must have been ideal for the purposes of any strong ruler.