hmm, this system makes only sense in a limited way
There should still be a limit on producable items per minute/hour/whatever. Only because you have 100 workers doesn't mean you have the items/space for 100 items at a time... correct me if i'm wrong. You won't have 100 machines able to produce rockets, 100 for ammunition, 100 for weapons, 100 for armor etc., you'll probably have 1 per workshop. More workers around the same machine won't make it go faster. Also the theoretical 1 minute per item makes only sense for mass-producable or really really simple stuff, perhaps wooden stakes to drive into the alien's hearts (though i doubt it will go through their armor... and they aren't vampires... eh... whatever
), more advanced weapons will just take more time.(cooldown time of metal and other stuff that has physical limitations...).
just my 5 cents on this
i guess there's no way to... hmmm... flag an item as "mass-producable" = 1 per minute or not "mass-producable" = 1 per hour, is there?