One pressure tank will give you volume for one minute, two pressure tanks will give you volume for two minutes. After that, all you have is what the pump can supply through the size of flow line you have. And that is only if the pressure tank(s) happen to be full when you start using water. The pressure tank(s) could just as easily be empty when you start using water. You have no control over this. With a 40/60 pressure switch, the pressure could be anywhere from 40 to 60 when you start using water. If it happen to be at 60, you will get volume from the tank. If it happened to be at 41, the tanks will actually be another load for the pump when it starts. So the pump will have to produce the amount of water you are using, as well as refill the pressure tank(s) at the same time. While the pump is refilling the pressure tank(s), you will be starved for volume in the house.
Pressure tanks where never designed to give you volume or stored water, only to prevent the pump from cycling on and off too often. A 119 gallon pressure tank only holds about 30 gallons of water. Even with two of these, you will rip through 60 gallons of water quickly in the house, then again, all you have left is what the pump can produce through the size of line you have. Your stored water is in the ground. There are millions of acre feet of water stored in the aquifers under our feet. This is where your volume of water comes from, not a pressure tank. You just need a large enough pump, and large enough water lines, to supply the amount of water you need. Then if you have a device to limit pump cycling, even a 1 gallon pressure tank is all that you need.