In hindsight my question is would Mossies have been better in all roles and I have seen no evidence that proves they would not have been.
This was the original proposition.
...and not ?
Why didnt bomber command drop the heavies altogether in favour of mass mossie atacks.
But the answer to your 2nd question is above. The Mossie could have performed much that the lancaster was asked to carry out. Further it could have done so with fewer net losses.
There were some interesting challenges to overcome to gear production upto the figures required.
In the UK it was (mainly) the Automotive and electro mechanical industries that upgraded their training to meet the needs of increased aircraft production. Skills whilst different were transferable.
Yet the Mossie was a laminated monocoque construction based upon woods and resins. This was actually closer to furniture based engineering. A similar problem befell early Lagg production in Russia. The materials and techniques were basically foreign to the mass production aircraft industry of the day.
It would have become one of the most produced aircraft in the war to achieve the same effect.......... Over 5000 lancs and halibags were produced to maintain the bomber force required of the RAF (and they wanted more).
Given the average bomb load ratio was one of 1:5 then based upon like for like survivability 25,000 Mossies would have to be produced. Given a 20 % increase in survivability then (with a ratio of now 1:4) we would still have required a total production of approaching 20,000. Even if we think these figures do the Mossie a disservice a final ratio of 1:3 gives the same total overal production requirement as met by the the IL2M3!
If I read Sharp & Bowyers version of the production evolution from Hatfield to Leavsden and then on, its clear that de Havilland was forced into such a high level of subcontracting that Mossie production became (famously although it should have been infamously) a cottage industry. He could not keep up with the orders he recieved from the air ministry!! Never mind a 3 to 4 fold increase.
To up gear this was beyond the capability of de Havilland although I am sure that if someone like Beavorbrook had determined that it should increase then de Havilland would have been pushed aside to allow Nuffield or some other organistaion to take over.
We should not dismiss the issue of pilots either. When Harris wanted 1000 bombers he was short of 400 trained pilots. He had to take reserve occupation pilots out of rear fields and go beg the fleet air arm for theirs. Of course later he had the benefit of canadian squadrons filling his ranks but even so from the above we note that Mossies would have required a training regime of some 3 to 4 times the number Harris needed for his Lancs.