I think Schweik and Nuuumannn are both trying to raise valid points that the other is missing.
If you are bombing say an oil refinery tonnage of bombs on target is definitely a prime consideration. The problem with a 1000 bomber raid using a lead bombardier is that the area plastered is massive and if that lead bombardier is a small distance off in his calculations then few if any bombs reach the target and any nearby towns get obliterated instead. Precision strikes always have lower civilian casualties. And yes Operation Carthage killed more civilians that military but that does not mean that every precision strike will do so.
True - to a point. The point becomes somewhat obscure whn one considers that there were several 'lead crews' within a Combat wing - one (or two) per BG.
If you are after air superiority, and follow Kenney's methods, then sending 1000 B-17s to bomb a single fighter aerodrome complex to smithereens is a massive waste of resources and will kill a lot of civilians. Sending in a small number of Mosquitoes would be the logical way to do that task. It is horses for courses as they say.
Incidentally, Kenney took command in the SWPA almost 2 1/2 years after the start of the European war where first the Germans targeted civilian (London etc) and industrial targets but ignored the airfields. Their way to deal with the fighters was to draw them into the air to dogfight them.
Then the Brits got air superiority and proceeded to targeted civilians (Hamburg, etc) and industrial targets but ignored the airfields. Their way to deal with the fighters was to draw them into the air to dogfight them. The advantage in that always lies with the defender as he can make an emergency landing and save himself and his aircraft while the attacker not only does not have those advantages but he must watch his fuel and break off and head home if he is to make it across the channel. At that stage he loses a lot of his ability to manouvre for defensive purposes.
Kenney rejected the tactics used first by the Germans and then copied the Brits and instead of sending out aircraft to draw the Japanese into air to air combat he decided that the fast and sure way to obtain air superiority was to destroy the Japanese aircraft on the ground, and to destroy their airports so they could not fly in replacement aircraft. That was a far better way to reduce his own losses to air combat, especially as the Japanese predominantly had plenty of combat experience and his crews had little more than basic training.
Kenney was not tasked with destruction of Japanese industrial capacity. His tasking aligned with Nimitz/MacArhur strategy to confront, destroy or bypass Japanese island strongholds on the road to gain strategic airfields for the bombing of Japan. His targeting included airfields, ports, shipping/logistics - largely tactical in support of Army and Navy suface ops.
The differences between Japanese capabilities and German capabilities to render a bombed out facility or airfield was significant. The Japanese never had the capabilities of our CB units to either repair construct operable airfields in a short time. Their logistics 'lines' were long and slow. Our (Allies) interdiction capabilities were overwhelming (submarine, surface shipping) and ports were bottlenecks as staging points and easy to interdict.
Ergo, the tactics were necessarily different. Additionally, airpower targets were both simpler to target and attack for maximum effect - with expectations for long lead times to rebuild/repair/resupply.
His tools of choice were largely available and not conscripted by RTO/MTO priorities, save the P-38 - and as you noted he 'upgraded tactical capabilities' of A-20, B-25 to operate very effectively - Had Japanese airfield area flak defenses been on par with LW, I believe A-20/B-25 losses would have been prohibitive for low level strikes. Granted, lead times to detect impending strikes would have been less for most Japanese strikes.
Fighter defenses of the islands (i.e. Truk, Rabaul, etc) were neutralized by USN, and achieved by RAAF/AAF in Solomons as replacement fighters achieved air superioroty.
For that he used, among other things, the nearest American equivalent to the Mosquito as a multi-role aircraft that he had available, the B-25. Replacing the navigator with a bunch of 50 cals and hanging some more outside the cockpit, both as devised by Pappy Gunn, made the B-25 what could almost be described as the American Mosquito FB.
Then he flew them at altitude to the target, not a choice because of the multiple 13,000 foot plus mountain ranges, and went in and straffed and bombed the Japanese from low altitude. And unlike in Europe where the attacking aircraft lined up like ducks to attack a target his crews often attacked targets from multiple directions at once so that the AA forces did not have a long string of targets that they could shoot at.
Although the Germans had far better AA and radar than the Japanese the advantages the Mosquito brings to doing the same in Europe are its ability to outrun most fighters and it had very low radar signature making it harder for radar to find and track. Also AA is nowhere near as effective against low flying high speed aircraft as the AA crews have little or no time to train their guns on a small target that is only in visual range for seconds.
On the last point, German 20mm was extremely effective on fast low flying targets. The VIII FC lost 1.5x fighters to flak vs air to air while strafing airfields.