What "balanced" means is simple: The total wire length and type from every positive battery terminal to every load or charging source in the RV must be identical, and the total wire length and type from every negative battery terminal to every load or charging source in the RV must be identical
A simple test will intensely "question" your assumption. All connections being sound test two batteries. One with foot long 1 awg cables, the second with ten feet long 1 awg cables. Apply say a 50 amp potential. Surprise!
It takes a lot of differential meaning cable length difference to cause a significant difference. .01 volt is not significant. Assurance is made by using sufficiently appropriate awg conductor. The differential would become objectionable if 10 gauge wire wire substituted for the 1 awg and I am talking purely the difference in cable length versus voltage differential. This can be expressed with circular mil resistance versus ampacity per foot, formulas but why bother?
