But -- 60 production for a factory that produces +50%? And 4 of them?
It's a no-brainer to build all 4, unless you run into health issues -- and even then, -4 food for +200% production is rarely a bad move.
I find that in the 1936 scenario, I spend the first upteen turns building factories everywhere, because it is such a no-brainer. And it is so effective (it triples my total production) that it seems abusive.
It also reduces the usefulness of the industrial civics. +100% on top of +200% is only a 1/3 boost to productivity.
...
If destroying the factory is the problem, either:
A> Making it harder to destroy the factory, or
B> When you destroy the factory, add a partially-built factory to the queue.d
In the current game, in a matter of a year, I can take Kuwait and turn it into a military powerhouse...
If the factories cost more, the locations that are top-end producers can be rarer and less arbitrary. Industrial heartland will mean more than just "where the resources on the ground are", but rather represent a huge massive pre-start-of game investment in industry.