I've not personally tried this, but... http://www.iotaengineering.com/pplib/balancedcharging.pdf
Perfect? Pretty much not going to happen. But assuming they are the same age, make and model, the idea to have the same resistance across each string. In this case a since you have so many strings, You should incorporate a busbar for each the positive and negative battery cables;Use the same length and gauge cables to connect each battery.
2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.
There is no "opposite diagonal" connection with a buss bar. Every battery gets it's own cables.
Last I checked everything connects to the buss bar. If anything the loads and charging connections would probably work best at the center of the bussbar.
Can you explain why?
My guess is that the connections (battery posts and buss) are likely to be more of a problem than the buss itself in terms of resistance.