Hello Vinzenco
why impossible? It is clearly stated that both A-5 and A-6 figures are with flamedampers, ie with 5% less power and more drag. so slower than without them. In A-3/R2 the external loads are clearly stated, nothing like that in A-5 and A-6 rows. And normal Rüstzustd. B and C (long-range bomber) are with internal bomb loads, at least in Flugzeugtypenblatt for He 177 dated 1.1.42. A-6 had only the forward dorsal turret, so less drag, it also had a tail turret, so it has a bit different fuselage than A-5.
Juha
5% of power is around 1,6% in speed i don't think that the drag of flamedampers is near of hs-293. the limited difference in speed for 2nd row and 3rd row we agree that is probably drag derivated, but as are descript the weapons on the image 2nd3rd row have same weapons.