Powerbuoy;
Nice, accurate diagram and a very small file to do it, 2.2k and it conveys the information perfectly.
My old 12 volt setup was exactly like that.
12 T105 Trojan 6 volters seriesed in pairs then those pairs paralleled. 12 volts at 1350 AH. If I recall right they are 225 AH at 6 volts.
Now it is split into a 24 volt bank at 450 AH and a 12 volt bank at 450 AH.
Just backing up your schematic with real world experience.
Cheers.
TomW