The root of the answer is that symbol of healing is a divine spell, and permanency is an arcane spell, and it must be the same hand that casts the spell and the permanency. Divine magic in general does not always mix easily with arcane magic, and divine healing especially is troublesome.
That Razmir's 'priests' can successfully heal their parishoners, without visibly using Infernal Healing, is unusual; if any wizard with early-Sevar-level Spellcraft could create a Ring of Cure Light Wounds as readily as Sevar made her Tiny Swords of Glibness (also for a spell no arcanist could stabilize), what Razmiran's priesthood could do would not be exceptional enough to fool anyone.
In fact, a lot of sensible educated people in Razmiran shrug and accept that, in real life, Razmir's priests probably just worship a god and get spells from Him. Because why go to all that trouble and do something nearly impossible - namely using arcane magic to imitate divine healing - just to put on a supposed lie that doesn't obviously benefit Razmir that much, compared to Him just saying that He's a ninth-circle wizard rather than a god?
It's a lie that works because Razmir figured out a way to mix arcane magic and divine healing on a level that most 9th-circle wizards can't.