Seems to me if you have a smaller battery bank it would not take as much solar to get them charged up.
However, the amount of solar you need relates to your daily usage, to replace that daily, so now having that much solar, it turns out that (gosh!) if you have a smaller bank then you will have more solar per battery than if you had a bigger bank.
Never mind how many batteries you have, just replace your daily usage. The number of batteries is for cloudy days--how long can you go before the sun comes out again.(including just for overnight!) Has nothing to do with your solar requirements.
Well, you do need one battery!
