Yeah, I usually go into the civ4eventtriggersinfos.xml file in your bts/mods/fallfromheaven2/assets/xml directory (or something to that effect) and change the iweight value under circle of gaelen from 200 to -1. In that case, Gaelan becomes an automatic reward to the first civ to tech to sorcery. Usually that's you, but on higher levels with the sheaim or amurites present, you might be faced with an AI obsessively teching toward sorcery at all costs, so there is some balance.
Just a few cautionary notes:
Always backup your original file.
If you use vista, you'll have to change the security properties on the ffh directory to allow you the user as opposed to you the user/owner/administrator of the computer (and why can't vista realize it's all the same person? <-rhetorical) to have save write access to the folder.
I haven't bothered with the gaelan change since the move to .40 - waiting for the patches to settle down, as you'll have to change the iweight value with every new patch.
Chances are you could apply the same thing to Mary Morbus, but I like some randomness. Free twincasters for the sorcery gamble are a fine reward though.