Multiple Production per city

[c3p_main]

The thing that bothers me in civ is that you can only make one thing in a city per turn. In reality their are multiple productions per city. I Propose that in civ4 or 5 that you can divide up production to the citizens, but only as much as there are citizens. for example if you have a city size of 7 that you can make 7 tanks at a time as long as each citizen had sheilds or you could make 1 tank at a time with 7 times the speed. and you should be able to produce more than one factory per city