priests

[Quitti]

Some nations just don't get good priests. It's there due to thematic reasons or due balance - h3 suddenly brings up whole new set of spells to be used (like instead of every priest having to bless once, they can push one more banishment or sermon of courage instead when just one divine blessing is fired up). Sword of justice and Sword of injustice both give +1h, barring that you could do a communion since it also boosts the holy level of priest participating in it, in addition to (other) magic paths. If all else fails, you can craft 4 slave matrixes and one crystal matrix, give slave matrixes to normal commanders and the crystal matrix to a h1 priest - divine spells don't cause extra fatigue or cause very little of it so having a holy communion doesn't kill off the slaves instantly like it's easy to do with other magic paths.

[Wrana]

One more thing - communion only boosts levels of priests who are already mages. So be careful who you include as a master. The same goes for Astral spell Power of the Spheres and Crystal Shield (which casts the same spell) - it also boosts levels, but only for priest/mages.
Actually, as Sauromatia you can use Sabbath to boost holy levels: you have many Blood mages, some of which are also priests iirc. One Sabbath Master and 4+ Slaves give you Holy 3.
Another thing I didn't test - there is a Hell Power spell. It requires Blood3 and boosts all levels by 2, also giving a Hrror mark. I am not sure whether it boosts priest levels but it should - which may be useful in a pinch.
Also there are some summons and mummification, but those above are easier to do.

[earcaraxe]

Do you mean if the master has only levels in holy (so he isnt a mage) he wont get bonus levels in holy?

is there any summons for sauromatia that has holy levels?

by mumification you mean the ritual of rebirth? does it give holy levels?