Or we could look at the code, which shows that POPs with good needs fulfillment are more likely to promote - and since farmers can promote to craftsmen, and probably will, that's likely to influence the number of craftsmen you have when subsidizing...
How the factories are doing, conversely, has nothing whatsoever to do with the POPs logic about becoming craftsmen. They don't check. They just decide3 'I am going to promote', then role on a weight table to see what class they promote to. Since the only checks they do for 'shall I become a craftsman' are 'is there work for craftsmen?', 'are craftsmen unemployed?' and 'am I in a colony?', they clearly don't give a hoot about how well the factories do.
As for tariffs vs subsidies - it's just a sales tax, no other effect. As near as we can tell, it effects your own internal produce as well, as POPs don't bother to check what the cheapest goods are - they buy on the prestige order, with the highest countries selling and buying first.