First off, you do not have to be a priest to know the scriptures, or to understand specific bits and bobs of it.
The idea that a culture who has been spacefaring for centuries, even millenia, would still rely on wet-naval tactics is, in my eyes, very far fetched.
I'm sure the navy is competent enough to have their own 'dialect', pretty much like every other military organisation in the history of humanity.
maybe "priest" isn't quite the right word then. I'll come back to this later.
The point is, that they
don't rely on wet-navy tactics.
However, there may be much literature that discusses battles and campaigns (possibly during the Reclaiming on Athra), that is still referred to in modern Amarr military theory, which to a particular point of view, would seem outdated.
Commands would be in a similar fashion as mentioned in another thing. People don't say "Commence targeting procedure on blasphemous rebel Evanda Char, and fire when ready", they say "Evanda is primary".
So, they'd say something on the lines of "Garum & Zakara. Alpha squad is Garum."
So, consider this scenario:
An Amarr-Caldari group is on a joint exercise. A Caldari is observing on the Amarr command centre. The Amarr admiral is talking to some other officers.
Caldari: "Who is that officer the admiral is talking to? what is that symbol on their uniform?"
Translator: "She is an advisor, one that is well versed in the Scriptures."
Caldari: "The Scriptures? those holy books of yours?"
Translator: "Quite."
Caldari: *thinks* "A priestess of some sort, hmm." *listens in* "What are they saying?"
Admiral: "the opposition forces are located here, here, and a smaller group here"
Advisor: "the parable of the lobster and the coral would apply there"
Admiral: "And what of these?"
Advisor: "It is written that at the battle of Udor, the Amarr were victorious."
Admiral: "Then it is so."
Translator: "The Admiral is asking the advisors opinion, and she relates passages from Scripture that are relevant to the situation, including the battle of Udor."
Caldari: "Udor? that is on Amarr Prime, isn't it?"
Translator: "Quite. The Udorian fleet misjudged the wind, and the Amarr crossed their T, which led to their defeat. It was a great victory."
Caldari: *writes in report to command* "they have priests to quote scripture, and think surface fleet battles are relevant."