[Endoperez]

Any unit can be a god. The game doesn't track where a unit is used; a unit could be recruited as a commander, as a unit, summoned leading a group of its copies, available as a pretender etc etc. Whether this unit is a Fomorian God King or a puny Warrior, there's no difference - they are just units. The source doesn't matter. Availability doesn't matter.

"13" is a unit named 13, just as "light infantry" is unit called light infantry. This applies for everything. Inside quotes, everything is text, not numbers. "13"+"1" is "131", while 13+1=14. If you want to choose with number, leave quotes out, and double-check that you didn't make any typoes.

If the game tells you unit isn't in the game, it means it didn't find anything matching what you wrote. Whatever you meant is totally different matter. Say, unit 19350 won't exist, if you meant 1935.