sequential turbos?

I had a crazy idea to run sequential turbos. idk how but I figured I could get some throttle bodies and use them as bypass valves and make up a program that opens and closes each correspondingly based off whether the big turbo is spooled up or not. they would feed off the same manifold the smaller up top the bigger below and they could each feed into a y pipe with the throttle bodies acting as a bypass valve before it gets to the y. they could run into the same intercooler (I was hoping) but idk if I would actually lose power by not going big enough piping for the cfm of the turbo or going to big. I am worried about using too big pipe for the little turbo when it gets out the y and I think I might have to do some dumb shit like put the y at the intercooler and have the bypass valves there and another y pipe going out with more ypass valves and even more bypass valves at the end. idk I need to do more research and thats why I'm here

also, would it be easier to go carb or FI with a big turbo?