Hi Joe,
I think you raise some valid points but the situation at Guadalcanal was very different from that at Midway:
1. Attacks against Guadalcanal employed far smaller numbers of Japanese aircraft - defenders frequently outnumbered the Japanese fighters.
2. Guadalcanal benefitted from earlier warning via the Coastwatcher system and the defenders always knew from which direction the Japanese would be coming.
3. Guadalcanal had more fighters available both in raw numbers and in the numbers that could be tactically massed (at Midway VMF-221's 4 Divisions were committed piecemeal as they were considered discrete tactical elements).
4. Japanese fighters had less combat time over Guadalcanal - their operating bases were 200 miles more distant from Guadalcanal than were the Japanese aircraft carriers from Midway.
The net result of these differences was that the USMC and USN fighters were able to mass more defensive fighters at higher altitude than was achievable at Midway against a less numerous adversary who had less combat loiter time over the target. Given these differences, it's hardly surprising that the USMC and USN pilots at Guadalcanal did better. The drawn-out nature of the Solomons campaign also enabled tactical evolution - early results against the Zero, IIRC, weren't particularly good during the early phases of the battle for Guadalcanal but they improved as experience increased and tactics evolved.
Bland kill/loss figures don't represent the subtle (and sometimes major) differences in tactical conditions between locations that have a tremendous impact on the outcome of tactical battles.
As I said, the USMC interception at Midway was just one combat, and one combat is always going to be 'different' than a long series of combats just from statistical variation with evens out in a big set of statistics but doesn't in a single case.
But, as has been covered many, many times on this forum and by now I think people should have gone and read up on it and know it's true, if you take all the combats beween Zeroes and F4F's in 1942:
-a signficant % did not follow the set piece of high altitude interception of escorted twins; in fact one of the earliest significant successes by the USMC Cactus AF F4F's was against a carrier strike by Ryujo against G'canal. But there were many other combats that didn't fit the stereotypical mold, the USN carrier based F4F combats certainly didn't, and moreover the 'bland kill ratio' didn't seem to systematically vary based on the type of combat, nor suddenly get much worse when the Zeroes got bases closer to G'canal (from October).
-the kill ratio didn't actually change a lot over time at all; even into 1943. The worst outing ever by F4F's v Zeroes was at the opening of the G'canal campaign (USN a/c) but was bracketed by better performances both before and after that.
The fact that the VMF-221 interception was just one combat is in short a better 'defense' of the Buffalo in US service than supposed huge disadvantage in that battle that never affected F4F's in other battles (or in that one too). But again, the people actually flying both a/c thought the F4F was superior; and OTOH the F2A result in that one combat was rather of a piece with the Buffalo's fairly dismal record otherwise against Japanese fighters. So as I've said before, it exaggerates to call the Buffalo some special absolute terrible a/c, but the service that flew both it and the F4F didn't think the F2A's misfortunes were just a fluke, and I think a bit more weight should be given to that before implying the 'surely' the F4F's very unusual (for 1942 Allied fighters) parity with the Zero was all 'circumstances', or 'tactics', and had nothing at all to do with the plane. It was likely a mixture of factors including superiority of the F4F as a practical combat plane over some other apparently similar types on paper like the Buffalo, and even some arguably superior types, on paper.