I think industry branch is too nerfed.

3 focuses gives you 4 factory, other 3 focuses gives 4 military factory.

6 focuses * 70 days = 420 days.

just compare German 1 focus gives you 6 factory!

if generic focus tree is for minor countries, that didnt have factories at the start of game, it need buff factory count or reduce focus time.
For example

70 days, 3 focuses - 2 factory, 3 factory, 4 factory
or
35 days - 2 factory, 70 days - 2 factory, 4 factory