Very good, thank you chuckfourth - your post shows the detail needed to isolate why our experiences are at odds, and why your Turn 3 fuel levels are so much lower than the ones I see in my own games.
Simply put, your corps HQs are over 20 hexes from rail head on Turn 3, which is caused by retreating all Soviet units so that Panzer divisions can be moved the maximum distance eastwards on Turn 2.
This is a situation where Panzer divisions are a bit further east than historically achieved, but not much. It is also unusual (though certainly possible) for Panzers to advance so far on Turn 2 without meeting any Soviet stragglers that need a hasty attack to free clear terrain hexes of ZOC. In both of our examples, panzer divs are farther east than historical results, so we need to look further to find the cause of the discrepancy.
In real life, supply throughput decreases as an exponential curve the farther supplies have to travel. In WitE, this is approximated through several linear functions, but there is a discontinuity in the decrease when the immediate HQ goes from 20 to 21 hexes away from railhead.
I haven't run an actual test game, but I can state that I do not see these very low supply levels (I see 30-40 MP) for two reasons - first, I keep corps HQ within 20 hexes of railhead, and second, my railheads are farther east.
"XXXXI panzer corps is east of Tallinn on the gulf of Riga the three divisions have 9, 15 and 14 MPs. They are just within 5 hexes of their HQ. Corps HQ is within 4 hexes of 4th panzer group HQ Rail has been repaired as far as Siauliai so 4th panzer group HQ is 18 hexes from railhead, XXXXI panzer corps is 22 from the railhead."
This places your corps HQ at about hex 65,20 which is 22 hexes from Siailuai. (Note that 4th PzG HQ being 18 hexes from rail doesn't help the corps or divisions get fuel). In my games, the railhead is a few hexes further NE, near Jelgava. My HQ, if in the same spot, would be within 20 hexes of rail, so both corps and divs would get normal supply, not isolated. Even if my railhead was at Siauliai, I would simply place my HQ at say 64,22. This might require my panzers to be a hex or two behind where yours are - but they'd have 30+ MP to play with on Turn 3.
"XXXXVI panzer corps is just west of the Dnepr on the northeastern corner of the Pripet marshes its two divisions and one regiment have 12 12 4 MPs respectively. They are in friendly connected territory and within 5 hexes of their corps HQ. Corps HQ is 24 hexes form Pruzhany where the railhead is."
Pruzhany is at 55,66. 24 hexes east places your HQ around 77,62.
In my last start, my Turn 3 railhead was at 59,50 just W of Vilnius. Corps HQ was at 76,54 - so 19 hexes from rail. Divisions were five more hexes east, with a bridgehead in normal supply actually east of the Dnepr river.
Bottom line: You have exceeded a threshold coded into WitE, where the game's imperfect model delivers imperfect results. This suggests two questions:
1. Can the supply model in the game be improved? The answer is no in WitE (engine changes not practical), but yes in the forthcoming WitE2.
2. Can the supply model in the game be maximized through better play to avoid exceeding limititation in the code? The answer is yes, through a combination of maximizing railhead advancement and/or ensuring that corps HQ units do not suffer isolation penalties.