From the factory my Bayliner has...
Three 30 amp panels each with its own 30 amp shore power inlet, and separate 30 amp breaker.
There is also a rotary switch that can route
1. All three to their separate shore power inlets through their own breakers.
2. All three to shore power inlet #1 through its single breaker
3. panel 1 to shore power inlet #1 and panels 2,3 to panel 2's shore power inlet, and panel 2's breaker.
The generator has a single breaker that feeds separate generator breakers that are interlocked with the shore power breakers.
This factory setup provides significant flexability as to shore power, covering almost any combination of shore power availibility.
I carry onboard a 30 amp cable, and a 50 amp cable with a 30 amp wye adapter.