Over the 6 years I have played with lead acid batteries, inverters, Victron components at my sailboat just to learn that it's much more complicated system or ecosystem as whole than one might think. No matter how well you plan it and how good components you use in your setup there is always one weak link in the chain which destroys the whole setup performance. And 12 V system is the last setup you should try to do something else than 12 V components. 

Bus has 24 V system, which is not much better so lets keep it for the bus systems and do separate system for the living space of the RV.

So in order to try to avoid the mistakes and learn from the lessons I have experienced from sailboat I choose 230 V portable power station as ready made battery system for my RV. It has the battery (4-12 kW), battery charger (2900 W), inverter (4000 W), PV charger (2600 W), generator auto start and stop features ready factory build in. Designed, factory made, tested, 5 year warranty from one place and nothing to install other then plug in the 230 V power cord. Full remote administration, notifications and reporting in phone app. Couldnt be much easier to build and everything works together with warranty. No 3rd party parts or installations to void the warranty or whos blaim was what and which? One accountable reseller and manufacturer do deal with if there are problems. Easy to replace and maintain.

I will rethink my sailboat electric systems again after this and get rid of separate inverter, charger, PV charger,... and replace all those with one portable power station.