[rotorwrench]

You have a point there. A switch can be compromised by corrosion even if it originally was rated for the current load of the system. A 20 amp circuit breaker or switch can be used after the starter switch to isolate the battery. The 6-volt system needs the 1 AWG cable for power & ground to insure that the starter will function. A switch on the other side of the starter will still isolate the rest of system and a much smaller switch can be used. The starter likely pulls a lot more amps than anything else in the system. The battery can handle that but it needs those 1 gauge cables to be intact.