Use for Battery Disconnect?

I use 2 round marine type battery swithes on my boat which has 2 engines with 2 starting batteries. I screw the switches to the bulkhead that is under the top step in the companionway to the cabin area.......where it is very easy to access. I also have 3 larger deep cycle house batteries under the step. The switches have 3 positions; off, 1 and 2. Also there is an output terminal on each switch. So theoretically I have 3 banks of batteries; the deep cycle bank of 3 that I use for anchoring out ( sort of dry camping on water) Those are connected in parallel and attached to terminal 2 of both switches. Each starting motor battery comprises a bank of only one battery each. One of these goes to terminal 1 on each switch. My converter has 3 output terminals.....each one of these is connected to the battery switch terminals. This works for me.
For my camper, I would do the same but only have one battery switch. Same deal.