I presume that if you're on shore power, you'll want to run everything on shorepower. I mean, why would you run a genset or cycle your batteries while on shorepower?
If that's the case, just put EVERYTHING on the same breaker box (except the house-battery charger), then run your power lines in from shore/genset/inverter into a 3-position changeover switch like this: 3-position changeover switch
If you're running on battery, just don't turn on the heavy draw stuff. This gives you the option of running those heavy-draw items on battery if absolutely necessary (maybe it's 120 degrees out, and you just need to run the A/C for a few minutes), simplifies your overall wiring, and gives you a single panel for all your circuit breakers.