I guess I am still failing to explain what I wanted to discuss in this thread.
I am not interested in the historical HE 119, but rather, WI the concept of a twin engine aircraft had shared the 'in-fuselage' layout, in its original design?
Well, I think that the Heinkel 119 proved beyond all reasonable doubt that it was both possible and had certain aerodynamic advantages. We explored this to some extent in my Blackburn Behemoth thread. As to why it was never proceeded with by the Germans, there are many answers.
The He 119 was only a technology prover, and was never considered a practical war plane.
Off the top of my head, I can't think of a practical contra prop aircraft the Germans built. It may have just never occured to them, or maybe they didn't fancy it.
Part of its amazing performance was bought with surface evaporation which was expensive, complex and vulnerable to enemy fire. A bigger development would probably have inherited this.
The Lw had such high hopes for the Ju88 and the Ju288 that it was never considered necessary (this was apparently Udet's reaction when first shown the Heinkel 280 prototype - piston engine fighters are winning the war. Why would we need this?)
If you wanted to make it a bomber, and have the engines in the fuselage on the centre of gravity, where would you put the bomb bay? The Brits in the late 30s would have put small bomb cells in the wings, but Germany was already using much larger bombs. Carry them externally and you lose your performance edge.
It would be possible to make a Zerstörer out of it. It would be fast and more manouvrable than a normal twin. However, with the streamlined nose the pilot's visibility backwards would be non existant, and putting a gunner's cupola in the slipstream would increase drag considerably. Remotely controlled guns were less than succesful in German aircraft of 1941-43. Then there's the question of where you'd put the forward firing armarment. OTL the Germans prefered it on the centre line. The He119 had a four bladed propeller to absorb all that power. This would have complicated syncronisation. Contra rotating props would have made it impossible.
However, if they'd wanted a dedicated unarmed recce aircraft, it would have been perfect with cameras in the rear cabin.
On a more practical level, buried engines would have been a nightmare to service in the field. Witness the He177 with its engines buried in the wings. Reltivey minor servicing meant removing the engine. In normal operation oil residue collected at the bottom of the engine bay and was a major source of fire.
Then of course there's politics. Messerschmitt was a great salesman, knew exactly whose arse to kiss and the RLM bought the Me210 off the drawing board. Heinkel had a sllightly more difficult relationship with TPTB, and it didn't help that he tended to build aircraft that were overcomplicated and expensive (He177, He100, He219). Given the 177 debacle, it's only fair to assume that a Super 119 would have been... problematic.