Again, idk, but I would not consider 5-9 thousands of fake accounts 'a large quantity of propaganda assets'. You can probably buy that amount of accounts for 10K, or 50K USD, or some similar sum. Chump change for a state actor, and commercial twitter farms existed for a better part of this decade, so there are, probably, 10's of millions of fake accounts to buy. Iran can probably rotate them daily for the whole year. (And I'm not sure that these accounts, being fake, can really influence people opinion).