2) Red Fleece is BB's pathetic attempt to eat into J Crew's ownership of non-greybearded shopper (i.e. the younger demo).
As far as your original question, there possibly may be no difference at all between them; for all we know, they may be outsourced to the same factory in China.
I don't particularly prefer Red Fleece but they're the right fit for a guy that's thin with long arms. Most sport shirts from other makes have 34" sleeves for size medium but RF appears to have longer sleeves which fits me better.
But you're right they're all made in China and likely from the same factory.