You have to pick whether you are going for the upstream /downstream set-up or try to put the negs on one pair and the positives on the other pair 8 feet away. Then look at wire size.
If you do the upstream/downstream thing, the inverter with short fat wires goes with the upstream side, that also has the Trimetric shunt there. Now the two 8 foot wires to the downstream pair don't need to be so fat at all.
The upstream pair will get worked harder on big draws and high amp charging, but you can swap the battery pairs sides every six months to achieve a sort of even wear over the years as another way to get some balance.
You have to do some picking and choosing what's more important.