As way of a start, in the Annexe II: Pertes (WNr) Connues des Arado 196 Allemands of the superb "les Hydravions de la Luftwaffe - volume 1" by J-L.Roba & M.Ledet [LelaPresse, 2008] the following WNr's have specific types allocated to them:
WNr.0170 - Ar196A-3 coded 6H+DM of Fl.Erg.Gr (See) Kamp
WNr.0174 - Ar196A-3 coded 6H+HM of Fl.Erg.Gr (See) Kamp
WNr.0183 - Ar196A-3 coded 6W+QN of 5./196
No doubt others here may fill in the gaps or confirm if all Ar196's between the two WNr's you mention were all Ar196A-3's
Cheers
Peter D Evans
LEMB Administrator