concern over battery banks

[GregOConnor]

I am redoing the house bank on my LXi and trying to make sense of the power path engineering. There now is not a way to shut off the house inverter supply 'so I think'. I did find a big marine style dial switch A-B-Both-Off but I see that only A enters and it carries all 6 of the oem Positive input. If you shut it off there is still current to the inverters and with the start batteries not enabled, I think the only path would then be via the detroit charging system. I fear this path would damage the detroit path so I removed the start batteries ( just took the neg cable off) prior to making house battery changes.
Way too many cables and I hope to eliminate redundant and unnecessary connections.

My concern is having a demand for power and a path that is undersized to carry that demand which then become a heating element.