To point out the obvious, as in most belief systems, a form of religion exists in zalanthas as much as our world, Religion is generally a loose belief system built around a set or group of stories contributied to one or more people or characters. History and human eveolution show these are usually taken from a specific region, people or race.
To point out a few of the most obvious, Nordic relegion, the gods of Thor, loki, and Odin, or Greek with gods such as Hades, god of death, or even the Roman pantheon.
All these relegious views base thier belief systems around the loose facts of human nature and makeup that sets aside anything we cannot explain and places it within the grasp of a higher power, giving it a name and saying there are reasons behind it we cannot explain. Why does the sky produce a sound like that? Oh, Thor is at his anvil, or battaling in his father's name, with the heros of great battles, and that is the sound of his battle, and the strike of Raggnerok, his hammer.
In zalanthas, we explain these elements away with names, and attribute people skilled in them, and particularly gifted in thier use as 'Gicker's.
How does Whiria controll the winds, and air? Why Is Ruk asscociated with earth and stone? And why do BOTH sorcerer kings subjugate those born with these skills, and instead insist that they be worshipped?
I think at least in some obscure way, the priests of these old religions still exists in both city states, and nearly ALL tribals, in both the forms of druidic 'Priests' 'Gickers can be likend to actual fabled Druids, in the sense that they control a particular aspect of the elements. (I think this would be a widely known fact in Zalanthas that particular people display usage of particular traits, more so in the south)
And in the north, with the more versatile Bardic system, who are a more acceptable form of real life views of a 'preacher' or better, a Storyteller, or travelling minstrell, who were renowned for being payed to spread religious views, or spreading that which they belived in.
Tek, who most would see as less honourable would have subjugated his old, in order to enforce his own view, a tyrant in the excuction of it.
Muk, who most would see as the most honourable one, not to say in the least that even Muk should be called honourable, would have more than likley rather have bent his foe to his own use, and thus proven his superior tactical awareness (a trait that can be seen in Tuluki politics) which can explain as to why Bards are afforded such respect.