With apologies to our Florida friend, that's not correct at all with our modern technology (research "inverter generators").
Yes, you can parallel them because they were designed to be used that way.
But PLEASE DON'T make the dead-man cable you describe. It's just way too dangerous and is very amateurish in that it shows one doesn't know what they're doing (no offense intended).
Either buy the correct connectors from an electronics supply place (called "insulated banana plugs") or buy the ready made cable for that purpose.
Good luck,
Scott