The recipes for molten iron and molten copper are less-better than the vanilla versions, requiring 75 crushed ores vs 50 vanilla ores. The big crusher productivity offsets this, which may have been your intent, but it seems strange to need to upgrade the crushers to break even vs vanilla.

The ore -> crushed ore recipes actually yield ~1.5 crushed ore per ore (1 guaranteed, with 50% chance of a second product). So the 50% increase is balanced out even without upgrading. Big crushers compound with this to yield 2.25x the resources, so with the foundries' productivity, that's ALot% more resources, even without any productivity modules included.