I think they are totally different design concepts (the 737NG/A319/20/21)
(boeing..update a 40yr old design just enough to keep the type cert valid)
(Airboooos a clean sheet of paper....)
Hmmm, the 737NG probably has about as much in common with the 737-1/200 as the A320 has in common with the Dassault Mercure, (often rumoured to be what the A320 was designed from) which is also a 40 year old design.
I don't think it was a clean sheet of paper
'ave a good night!