Connecting more than one lug to a battery post is asking for problems. Stud battery buss bars like shown above in this thread, reduce future issues dramatically. I do not use the word 'dramatically' lightly.
I even limit terminal stacking to (2) two per stud on a buss bar. OEM uses more than one per battery terminal but the cables enter the clamp lug and are crimped in the barrel of the lug.
I've run into countless wiring disasters where a customer has a pair of batteries and six or eight extraordinarily corroded wires and cables connected/stacked direct to the lead battery posts. I would loosen the nuts then tell the customer to get lots of boiling baking soda, go back to camp boil water, add the baking soda then soak the ends of the wire in the baking soda. It's a messy, frustrating, time eating job.
To pay me to do it was unwise. Expensive with a capital E. And the cost caused more arguments and bad feelings than any other I can recall.
If
"That's why I am asking YOU to do it".
If they balked and cursed at the cost of labor then it was 'Down The Road Dugan¨.