B, I've read the posts. And as I've said, the "discharge depth" argument is fallacious, it has no bearing here. The only other firm and clear argument about parallel batteries has been that they are cheaply built using readily available parts, i.e. the batteries from WalMart or Sam's Club.
And I've conceded that cheap sometimes is good. But aside from "cheap"...there have been no other arguments made that indicate anything *certain* about any advantage of parallel batteries.
At best, Dave has said that depending on various factors, in certain cricumstances, there may not be any disadvantage to their performance--and that's ignoring the extra failure modes that are possible.
I'm saying that any configuration which provides zero definite advantages, and doubles my chances of a failure, is a bad idea. Cheap batteries in parallel may be convenient--but I've yet to see any reason to think they're any cheaper, either. (Battery pricing being a very variable thing.)