General Question about ROM Chips and Repro Carts

I'm going to attempt making a Star Ocean repro cart, and I found the excellent guide on this site.

I'm only going to use one of 27C322, but I'll end up with two of the chips and in my musings of trying to decide what to do with the second chip, I though how cool it might be to have both the JP and English version on this same cart - clearly I'll have room for the two chips inside the cart. (I could also use the original mask rom, assuming that I don't damage it, removing it from the board.

I admit that I know next to nothing about how ROM chips work, but I remember seeing somewhere (I think it was a Neo-Geo mod) where you could actually connect two chips to the same "socket" and use a switch on one of the pins (Vcc maybe?) that would only allow power to one or the other chip.

Is this actually feesible, or am I completely crazy here?

As I understand it, if only one chip gets power on the power pin, the other chip's input protection circuitry will end up powering it too. It was probably a chip select or output enable pin that caused only one chip to put signals on the data bus. This is used even inside NES carts, where both the PRG ROM and PRG RAM are connected to the same bus, but the MMC1 pulls only one chip's output enable low at once depending on other address bits.