adding a casting progression

[blelliot]

Would adding a casting progression to the heirophant and dragon disciple prestige classes be too unbalancing? I was thinking full progression for the heirophant and a 3/4 progression for the disciple. Any thoughts?

[Urpriest]

The Pathfinder version of the Dragon Disciple has 3/4 casting or so, so take a look at that for comparison.

For the Hierophant, if the Archmage is fine with full casting then the Hierophant should be too.