It can be easy to increase, but when you have just a little, try to be a good Priest coverting 3 followers after spending 12 hours. Useless.
I played with another Priests before, but they became Priests along the way (they already had some oratory). Tried to start as a Priest... I found it better to spend a little in the academies to increase Oratory to justify spending 12 hours with a good conversion ratio.
For each their own.
If you want higher conversions since day one, spend before.
If you want to increase oratory and conversions along the way, just preach.
For me was better to not waste 12hours just to increase oratory without the expected results when you preach: convert people.
