So saying that from 1938-40 there are an additional 500 Bf110s, no additional Do17s, and all the new Bf110s are fighter-bombers, night fighters, or recon aircraft (i.e. more than double the historical number of total units in 1940) would they have made much of a difference as more capable fighter-bombers/ground attack aircraft than the aging Do17/215? I'd think they'd be more surviveable as they were faster than the Hurricane Mk.1 and able to out dive the Spitfire prior to the Battle of Britain (I think even after they were as fast as the Spit Mk.1 with 100 octane fuel and could out dive them due to the fuel injection system). They'd likely be more accurate with their more limited payload and be capable of ground attack once they dropped their load. During the Battle of Britain they could also do the hit and run raids on radar stations and airfields that Bungay talked about as their ideal use.
Examples of when the Bf110 would have been more surviveable than the Do17:
https://en.wikipedia.org/wiki/Operation ... n_Campaign
Clearly this is not a 'win the war' what if, so please don't drop in that line, that's assumed. Would it make a difference to the 1940 campaigns, including the Battle of Britain?However, Allied fighter resistance on the first day was severe, and KG 2 and KG 3 of Fliegerkorps II lost a total of 19 Do 17s between them on 10 May.[22]
However, over Dunkirk, the RAF fighters inflicted a high loss rate. On 2 June, 30 German aircraft were destroyed, including 16 Do 17s (4 from KG 2 and 12 from KG 3).
During the Polish campaign, the Do 17Z could use its 427 km/h (265 mph) maximum speed to stay away from most enemy fighters, and its light armament was effective. It also fought with success during the Battle of France and losses were relatively light, although when facing modern fighters like the Hawker Hurricane, the bomber proved slow in comparison and more vulnerable. When it faced British fighters during the Battle of Britain, it was shown that fast, well-armed monoplane fighters had changed the balance between bomber and fighter decidedly in favour of the latter. The Do 17 suffered in early raids.
Losses mounted and on 15 September 1940, the three Dornier-equipped Kampfgruppen suffered heavily, losing 20 shot down and 13 damaged.[26]
The losses for the Do 17 in August and September were considerable. In August 1940, 54 Dorniers were lost and another 20 written off due to technical problems and accidents. In September 50 more were lost, with 31 Do 17s and crews missing in action. In October another 36 Dorniers were lost.[29] Dorniers had improvised armament of eight machine guns installed to increase defensive firepower, but still were unable to counter fighter attacks.[30]
Edit:
Based on the November 1938-mid-1940 numbers for the Do17/215 that was probably closer to 1000 aircraft. So for the sake of argument that would be 1000 additional Bf110 from November 1938-July 1940 at a minimum not factoring in economies of scale. They would have to fill the recon, night fighter, and bomber roles that the Do17 did historically and would be more surviveable in all due to being faster.