I have found conflicting hints on the subject. Some points to Pholtus and others to Heironeous
As I was doing my research for writing background info for the Innspa / Adri region of the Living Greyhawk campaign, I found only hints (in the original WoG-Box), that Prelate Kevont was head of a state that was LG / LN in its majority. Thus I draw the conclusion that he worshipped one of LG / LN Gods of the Oeridian pantheon. That makes Heironeous and Pholtus both a first choice.
But there was an early dragon article (late fifties, early sixties), that spoke of a Prelate Anarkin, who was in charge around 578. As Prelate Kevont was head of state before that time and according to later products after that period as well, I came to the conclusion that the Prelate was elected. As elections couldn't be nation wide in a country that large, I thought some kind of committee was electing the prelates.
Someone else brought up the idea, that this was an ecumenical committee where all churches had seats, with the curches of H. and P. havinge the most.
Gary Holian suggested, that Almor followed an oeridian aspect of Pelor called Sol or Solan (I'm not sure on this right now) and there hints in the LGG that this was the main faith in Almor in former times (centuries ago). While I don't like this idea, there a lot of people, thinking it's a good one...
We made Prelate Anarkin a follower to Heironeous, whereas Kevont followed Pholtus.
A few suggestions (all admittedly debatable, done from memory, and at least in one instance are retroactive continuity reasoning) as to why or why not certain gods make the cut:
Pholtus- I seem to recall (but decidedly could be wrong and, of course, my resources are accross the US) that either the Prelate at one time, or perhaps one of the alignments of the populace was given as NG. Also, the heraldric device of Almor (on the now ancient GH gazateer folder) contains a (rising?) sun that is quite, quite different from Pholtus'. Such a lawful god isn't likely to appreciate such a deviation. Also, for a non-greater diety, adding Almor to Pholtus' flock would give him a _heck_ of a lot of worshippers.
Heironeous- Almor's army folded like a used dollar bill in the beginning of the GHawk wars. Not exactly what one would expect from a war diety. Ret-con, but very hard to reconcile.
Pelor- Alignment matches, sun diety possible match for Almor's heraldry, prior to the appearance of Mayaheine (sp?) a rather non-militant god- perhaps the Wars taught him a lesson, and my personal favorite (that I came up with myself)-
In the old GH Adventures hardback, most every nation has a magic item. Almor's are rings of healing made by their clerics . . . and one of Pelor's primary areas of concern is healing.
Just some thoughts for your consideration