So I posted in the general Attila mod section a couple of days ago but nobody answered.
Since then I have found out how to give the Sassanid trait to have more levies availible to other factions and also how to adjust the number (vanilla is 3).
What I achieved so far is to make you able to recruit e.g. 20 Germanic levies insted of 1 from puppets per turn. What I want to achieve however is to be able to levy better units, like Germanic Spear Masters or Scaled Clubmen.
However since I don't really know anything about modding I have mostly been experimenting so far, looking for something in the db-tables that distinguishes units you can levy from those you can't.
First I thought it would have something to do with the "unit_caste" entry in the "unit_set_to_unit_junctions_tables" and changed it but to no effect.
Then I considered it might be column "unknown39" in the "main_units_tables" but that didn't work either.
So please, if someone reads this who has an idea with even with only a slight chance of working I would be very grateful if you'd comment.