I used to have 4 30 amp outlets, two on each side in the middle and I hated the configuration, like to easy to trip on wires.
I moved 2 of these to the stern of the boat right next to each other, so now only have two.
I mounted them both in the cockpit
. Some sail boats have them right on the outside transom.
I always back the boat into the slip, never have any hookup problems. The wire does not need to run down the deck
Mine both go into the same panel and are split inside the one panel. * breakers, 4 for one 4 for the other. By the way, neutrals should be separate in the panel, but not all older boats might be wired that way. Some will have a shared neutral for these twin setups.