Defending your candles

[WraithLord]

Generally, building temples and preaching is the way to defend your dominion. However, is it possible to optimize?-
I mean for example, is it better to have 9 H1 priests preaching in one province or spread out in threes and preaching in three provinces?
When building temples, is it better to build in adjacent provinces or rather in non adjacent provinces (given its best to build temples in *all* provinces, buts hardly very practical)?
What of the following has better preaching potency?
5 H1 priests,
3 H2 priest,
2 H3 priest,
1 H5 priest,
With and w/o temple?-
Is it a simple linear equation?- N*H or N*2H (N, # priests, H- holy level)

What if you don't care about losing dominions in your lands but rather have a specific province you absolutely must have your dominion? (for example, when LA R'lyeh is your neighbor)

Any further tip on the subject would be most welcome