?? They didn't start bombing in Europe until August 1942. And didn't hit Germany until January 1943 ??
By the time the Americans were regularly hitting targets in Germany (June 1943) the accuracy of British and American bombers were comparable for the targets they were aiming at. Now the American targets were usually much smaller and more specific than the area targets the British went for. But if we are talking about getting results then not attacking the primary enemy targets until mid 1943 cannot really be regarded as being more effective than whatever mediocre efforts the RAF had prior to this date.
What I will accept is that the accuracy of US daylight bombers was better than night-time RAF attacks. But effectiveness is a function of not only accuracy but number of attacks
And? They were bombing by day and didn't need the electronic guidance systems the British did at night to try and find their targets. By day the British didn't have problems finding targets, night bombing required special equipment to make viable in most cases (coastal targets were reasonably easy to find though depending on moonlight). The problems the US strategic bombing had was one of tactics and methods rather than technology, as you said they had a delayed learning curve compared to the British, though even as early as 1942 they were much more accurate than RAF BC city bombing, which was area bombing. You can't say that the targets the RAF and USAAF were aiming at were remotely comparable. The US was actually hitting and knocking out targets in 1942-43 of rail yard or factory size, while the RAF was area bombing entire cities with mixed results and required many more bombers (and special weather conditions) to achieve results. The bigger problem for the US was following up on targets, which they had a problem with in part due to the lack of long range escorts. Look at the 1943 raids on aircraft factories and ball bearings, they did serious damage, but because they weren't followed upon they didn't do enough to really put them out of action for an extended period of time.
The RAF of course had their special bomber units, which were getting excellent accuracy due to their special guidance equipment or flying low, like the Dam Busters, but then they were also a handpicked elite and had years of combat experience.
In terms of not attacking primary enemy targets...I'd say look at the losses the RAF suffered bombing France in 1941-42 with their Rhubarb and Circus missions and compare that to 8th Air Force losses against French targets in 1942, as well as the bombing results. In part though it isn't necessarily a totally fair comparison as the B17 was quite a bit different than the bombers the British were using during the day.
Accuracy is crucial, as number of attacks is meaningless without actually hitting the target. It's just that depending on the target multiple missions are needed to make sure the target stays bombed out, because most targets will be able to recover with sufficient time and resources. Still, the Mosquito got better results generally than the Lancaster did for less resources and losses due to the accuracy. That is unless we're talking about city bombing where tonnage counts or the use of Tall Boys and Grand Slams or bouncing bombs for the same reason.
