Hi, Don et al,
I must agree with you, Don- the Loremaster's might have manipluated things a bit (alright, a lot), to get the crowns initially used- but by now to the average Jaimani those crowns are the definitive, defacto symbol of King/Queen-ship.
Additionally, comparing the United Church of Orhan to the Christian Church is pushing things a bit. The Christian Church combined both the functions of the Church of Orhan- and the Loremasters. The Earth has only had one God (whose actual existence is open to often spirited debate) and the Church manipulated things so that the only way you could find things out, was to ask a priest.
Whereas Kulthea has a whole pantheon- whose existence can't be doubted. So, it would be difficult in the extreme for whichever religious group to grandly declaim:
"I hereby crown you <insert name here> in the eyes of <favourite God>." without said Celestial personage actually putting in a personal appearance, to add a bit of gravitas to the proceedings. (Although, the Dark God's might be more inclined to put in a personal appearance.)
On Earth, however, as God has never actually put in a personal appearance- or at least not in front of reliable witnesses- the Church could justifiably get away with such claims. Also, because of the sheer power of the Church, both politically and economically, it could (and did) pretty much control puppet monarchs. Basically, they had the power to hire and fire Kings, through the threat of excommunication- the commoners were so cowed by that threat and fear of eternal damnation- that they certainly wouldn't have been happy being ruled by a ruler who had been excommunicated. Additionally, they could easily coerce other Kings into warring on another- under that pretext.
My personal take on the Loremaster's crowning the Kings, in Jaiman at least, is the age old adage of "knowledge is power". Basically, it's a power thing- the Loremasters are widely regarded as the most learned group on Kulthea- which is why many realms like to have a Loremaster visible in the Corridors of Power- and the more famous the Loremaster, the more prestige accrued by the Ruler. So, for a Coronation, who better to have than one of the most famous Loremaster's of all time.
("Sorry, Andraax is fully booked that day- but Kirin T'haan is free.")
All the Best,
Kevin.