Each of these archetypes changes something about how the cleric's domains work, and I'm not sure if they can be combined.
The Separatist chooses one domain from those that their deity normally offers and a secondary domain that can be almost anything. For that secondary domain:
Granted powers from the cleric’s second domain function as if the cleric’s level, Wisdom, and Charisma were 2 lower than normal (minimum level 1) in terms of effect, DC, and uses per day. This also means the separatist doesn’t gain the domain’s higher-level ability until 2 levels later than normal. If the second domain grants additional class skills, the separatist gains these as normal.
The Scroll Scholar gets Diligent Student, which
...replaces one of the 1st-level granted powers from her domains—the character gets to choose which of her two 1st-level granted powers it replaces.
Here are the ways that I could see this getting ruled:
- The archetypes cannot be combined, because both of them modify the Domains class feature
- The archetypes can be combined, but Diligent Student has to replace the ability from the primary domain, because that is the only domain power the cleric has at 1st level.
- The archetypes can be combined, and Diligent Student can replace the second domain's 1st level power, even though the cleric wouldn't normally get that power until level 3.
- The archetypes can be combined, but Diligent Student won't be usable until level 3 if it replaces the second domain's ability. In this case, Diligent Student functions as if the cleric was 2 levels lower, just like the second domain.
Is there an official way that these archetypes would work together, or are they / should they be mutually exclusive?