Thank you for bring up this point, I was remiss in not explaining the difference.
Correct, there are two additional single points of failure, the connections between the 6V blocks (discounting the wire and crimps). The first configuration has redundancy, the second does not, so the first is preferable. Increased reliability can be accomplished by feeding both strings to the same terminal point, instead of one string to the other.
At some point the amount of redundancy in your system depends on how much you want to take it. At the extreme you can have two totally independent systems duplicating everything including loads (electronics, lights, refer, etc.). At some point you have to decide how much redundancy to have.
Don’t get me wrong, I have spent a lot of time on this thread arguing for paralleling batteries as a means to improve reliability and capacity, and would advocate doing it the first way, but in the end it comes down to personal preference.
There are two types of fools...
One says this is old, and therefore good..
The other says this is new, and therefore better...