Yes, I should have been more clear.
In method 3, for three batts, the three pos links need to be equal and the three neg links need to be equal, but the pos links don't need to be the same as the neg links.
However, the three links for each do need to be able to carry the total current without adding a lot of resistance. The danger point for that is the junction where the three links have their lugs stacked. Better to use a buss with three ins and one out I suppose, to avoid stacking.
So loads and chargers to a buss with little or no stacking, then a single fat wire from buss to the junction buss with the three equal links from that to the batteries.