I think you mean to say that Marseille, claimed 17 kills in one day. DAF records only show the loss of 8 fighters that day. Other Luftwaffe units made claims that day too. Pro rating the days claims gives him less than 8 maybe only 3 or 4.
I take your general point, Marseille was credited with this, Hartmann with that, but the question here is what happened, not what pilots were credited with. But, "Fighters over the Desert" by Shores and Ring gives the following somewhat different info about Marseille's 17 credits Sept 1 1942 (I cut/paste following summary from somebody else's post on another website, but I have the book and checked the info, it's pgs. 168-170)
=================
Marseille's first mission that day:
4 enemy fighters claimed shot down (at 0926, 0928, 0935, and 0938 hrs) with 80 cannon shells and 240 machine-gun rounds.
According to Shores/Ring, these were the pilots in the aircraft which Marseille claimed shot down: Lt Bailey (1 SAAF sqn) force-landed his Hurricane; Maj Metelerkamp (1 SAAF sqn) was injured and had his Hurricane badly shot up; F/O Matthews (238 sqn) had his Hurricane shot down; P/O Bradley-Smith (601 sqn) had his Spitfire shot down.
Marseille's second mission that day:
8 enemy fighters ("P-40s") claimed shot down( at 1155, 1156, 1158, 1159, 1201, 1202, 1203, and 1205 hrs). In addition to Marseille's claims, Lt Remmer claimed one P-40 on the same mission.
According to Shores/Ring, six British fighters were shot down during an escort mission for bombers.
Marseille's third mission that day:
5 enemy fighters claimed shot down (at 1847, 1848, 1849, 1850, and 1853 hrs). In addition to Marseille's claims, four enemy fighters were claimed shot down by other German pilots on the same mission.
According to Shores/Ring, five Hurricanes of 213 sqn and one Hurricane of 208 sqn that were shot down approximately at the same time probably are identical with at least some of the German claims on that mission.
Shores and Ring list a number of additional Allied fighters lost in combat in Egypt on 1 September 1942 - although it has not been possible to verify the exact time (hour minute):
Sgt. Sowerby, 3 RAAF sqn, was shot down
5 SAAF sqn had four of its fighters shot down
2 SAAF sqn and 64 U.S. sqn lost three P-40s on one mission
According to Shores/Ring, some of these (at least one of 5 SAAF sqn's losses) are among the six fighters which were shot down when they escorted bombers and - probably - were encountered by Marseille on his second mission on 1 September 1942.
Due to Shores/Ring, the official Allied losses in North Africa on 1 September 1942 amount to 22 aircraft (9 Hurricanes, 4 Kittyhawks, 4 Tomahawks, 2 Spitfires, 1 U.S. Warhawk, and 2 Beaufighters).
=========
Total Luftwaffe fighter victories that day were max of 27 per OKL victory list, so Marseille's prorated score, without trying to figure out conflicting German claims one by one, and omitting the Beaufighters would be 17/27*20~12-13.
On other days it wasn't as good though. For example on Sept 15 the total German claims in the combats around 1800 were 21 (20 Kittyhawks+1 Spit), 7 Kittyhawks by Marseille; but only 6 Kittyhwawks were lost total, 2 others 'badly damaged' plus 2 Spits (at unknown time). One Kittyhawk was attributed to AA.
But as I said above, if *any* ace's score checks out at even 50%, that's almost surely better than the all-WWII average for all credited fighter victories.
Re: 'not belief' in Hartmann, it's not religion
, it's air combat records on each side. We can either find enough reliably two-side documented incidents in Hartmann's career to get an idea of his real claim accuracy, or else we just don't have a very clear idea how many planes he really shot down.
Joe