Bomber Command in 1939 was an investment in the future, not at all the cutting edge weapon that the Air Staff touted it to be. By 1937 even the Air Staff acknowledged it was a deterrent and incapable of delivering a knock out blow to Germany
The need to expand it, rapidly, at the beginning of the war caused an immediate contraction in the already limited first line strength as aircraft and instructors were required to make up the new reserve.
The high rate of losses, both aircraft and aircrew that the command suffered in its early operations, before these new recruits and aircraft became available not only endangered the existence of the command in being, but might have compromised the future force. The need to conserve and expand Bomber Command at the outset of war was second only to the requirement to avoid defeat.
That was the British reality in 1939.
Roosevelt's appeal to belligerents to refrain from unrestricted warfare was welcome to the British. When the Wermacht went east, attacking Poland, the British were happy to put into effect a policy of restricted bombing. The British also had to cater to their French allies. When Evill went to France to discuss possible attacks on various German targets, including attacks on the Ruhr, with Gamelin it was clear that the French believed that the less bombing the better. The French did not want to attract air attacks onto their own industries (which they believed to be more vulnerable than Germany's). All that was agreed were the types of attacks that were made historically by the striking force in France.
As for attacks on Wilhelmshaven, W.A.7(b) called for 'Limited attack with air forces alone on Wilhelmshaven'.
There were standing instructions for attacking the German Fleet or parts thereof at sea, incorporated into W.A.12, but the target(s) were hardly ever found, let alone hit.
W.A.10 was for the bombing of shipping in German mercantile ports, prioritising Baltic ports, but it was noted that 'This plan is not really practicable until Bomber Command is equipped with a larger percentage of long range aircraft'.
The very role of British bomber forces had come into sharp focus in 1937, encapsulated in the report of Sir Thomas Inskip. He wrote that (I'm quoting selectively, you can probably find the text of his 'aide memoire' online. It's in Webster and Frankland, Vol.IV)
'
The role of our air force is not an early knock out blow...but to prevent the Germans from knocking us out'
'My idea is rather that in order to meet our real requirements we need not possess anything like the same number of long-range heavy bombers as the Germans.'
'It seems to me that what we want to do in the first weeks of the war is to knock out as many German aeroplanes as we can...After which we can adopt a more offensive role, which I should hope might be based not on this country but on French or possibly even Belgian territory, from which the distances to the vulnerable German regions mentioned above are shorter.'
And, eventually, the political point.
'...the general suggestion I want to make is that, without loss of efficiency for our own purposes, we might substitute a larger proportion of light and medium bombers for our very expensive heavy bombers. In doing this we should, it is true, reduce in some degree our power of hitting Germany at the outset of war.'
Now, some might call all this contrarian, but it is the reality of the time. If anyone can see ways in which Bomber Command can do better at the outbreak of the war I'd love to hear them. This was not started as a 'what if'; It was supposed to remain based on the real constraints of the time. It would be great to have a few hundred Lancasters and fully operational crews, Gee, Oboe, H2S, etc., a Mk XIV bombsight, effective marking pyrotechnics and ordnance to destroy the intended target(s) in 1939. But NONE of it existed.