A lot of stuff I have to answer, please forgive me if I don't use quotes but only bullet points this tim
1, marching speed. It indeed does not make any difference if the Army in question is weak or strong. In contrast to attacking. Marching up to battle (be it pre-war in an allied country or in the war behind the front) could only made with a fixed speed (around 35km a day for Inf, 200km for mot, you can push it up to around 45 and 250km for a time, but no indefinitely, and only where the infrastructure doesn't suck ass. As in Moldova and the SU). I was referring only to marching up to the concentration area pre-war, NOT attacking the soviets after the war broke out.
2, if we talk operations, when and how many German troops could be amassed in Norther Moldova is the most central point. If we limit the concentration to 10 fast and 11 inf divisions (I know, you want to have more, but please let's see what could be made with the original amount), we have these possibilities:
A, depolyment starts only on the 12th June, 5th PzA gets priority. Till the 22th June it would be barely possible to concentrate the Army in the North, the very last division would still need one or two days to arrive and concentrate. The 11th Army's infantry only just begun to leave the Bucharest area, with the first rail-transport Div arriving fully around the 30th at the border.
B, As above, but the starting date is pushed up to the 2nd July. 5th PzA is concentrated fully, from 11th Army there is one Div concentrated, another rail-transported one is starting to concentrate (say, around 2/3 is already present) and a third, marching up on roads is still a couple of days (3-4) away.
C, To have meaningfull Inf forces in the North (be it 22nd June or 2nd July) you indeed have to start sending the divisions North much earlier - around 12th May to have everything there on time. Adding further 3 fast and 2 inf division would push the starting date back by another week, to not later than 5th May. Pushing 20+ divisions through bumper-to-bumper for 40+ days constantly would point everyone that is not blind that something big is up. Do remember, Rumania at that time was still neutral with every last ambassy extant. Sending troops North could not been sold as preparations against Turkey, for that you would need to concentrate in the South or more convincingly in Bulgaria. So for that ruse to work, you would have to send troops to the South, not to the North where the infrastructure was bad. I don't think, it would be impossible to send troops to the North (as instructors, etc) beginning in Mid-May (or even earlier), but that would be a gradual build-up not a massed rush. What would be a convincing amount that could be sold as instructors or border defence? North of Iasi (everything South of that line would not help you concentrate in the North) there were the Mountain Corps, parts of the Cavalry Corps and let's say another Army Corps (with a lot of Rumanian troops still marching up to the front as late as 30th June/2nd July). For less than 10 Divisions you don't need 10 Divisions of "instructors", but around 3 at most (one per corps). Much more and the game is up. I give you even two further for "Border Defence" but that is a bit of a strech. With 5 Divisions already there in Mid-May (or Mid-June), you only have to push 5th PzA (10-13 fast divisions) and the rest of 11th Army (6-8 inf div) through. That would lead us to:
C1: Movement starts only on the 12th June in earnest, kick off date is the 22nd June. You have around 9 fast divisions, plus the 5 inf in the North, the sixth inf still arrives on the 30th or so (or, if you want to have the other three fast divisions, not before the 3rd July)
C2: as above, but kick-off is the 2nd July. See point B, but with further 5 InfDiv. Please note, that if you want to have the further 3 fast ones, they could be barely concentrated, but you would not have any other inf div, just the already present 5. Pushing up the other infantry would still need around three further weeks (so you haven't saved much time by sending troops up North earlier. 10 days at most)
The real problem is the Infantry. They are just too slow to be deployed in a meaningfull timeframe, and with the infrastructure in place in Moldova you don't have much of alternate routes. Putting them on the railway isn't much of a choice either, because a, you would need upwards of two month for the 11 divisions and it would be b, obvious to everyone that you are concentrating in the North against the SU.
1,We agree that 5PG reaching operational freedom north of the Dniestr around Day 5 is plausible.
2, You argue that Soviet Motorized Corps counterattacks would prevent the trap closing in Galicia before SWF escapes, I argue that MC attacks barely slowed Ostheer's fast divisions. Schnelltruppen rapidly disengaged from such tank-tank battles (Dubno, Rassenai), leaving the infantry to fight them while the fast divs rushed on.
3, You question whether 5PG could have advanced 34km/day to reach Shepetivka and link up with PG1 (the required advance rate after crossing the Dniestr on D+5). I argue that 34km/day is an easily achievable rate for Ostheer spearheads in 1941, as the spearheads of AG's N/C advanced ~60km/day during June.
4, You argue that the ground for advance is not suitable for fast operations (did you argue this, or were you referring to deployment only?). I argue that the Second Jassy-Kishinev Offensive shows that massive mechanized forces traversed this ground rapidly during 1944. You respond - for reasons I don't quite understand but please explain - that Soviet movement is somehow different from German.
1, possible, NOT probable. If we go with probable, I would say 7 days, just to be on the safe side
2, could prevent a Kessel. You would need the 11th Army on soviet soil to fight the 5 fast coprs in the rear of 5th PzA, or else they can close the Dniester after 5th PzA sped away, and the soviets can retreat along that river and escape the Kessel
3, 34km/day is the minimum speed to reach Shepitovka in time to close the Kessel (assuming a start on the 22nd, any time later and there would be zero chance for closing it). If reaching freedom of operation in 7 days, the needed daily advance would be around 60km, so it would be a very close thing
4, You misunderstood me there. Moldova is not suitable for a fast deployment, if you want to leave the neighborhood standing. The difference between German deployment in 1941 and a soviet attack in 1944 is manyfold. 1, the soviets did not use only one road (state 11A) to march up to a very narrow geographical region, but attacked from multiple directions on a "broad" front. 2, the soviets did not care about shooting or tearing up enemy territory, they were able to advance cross-country through fields if there was a need. Germany obviously did not want to flatten their ally's territory while moving up. 3, if we only look on main roads for advance, the soviets could use the border road (state 26/24A) and the intermediate road (state 24) for their drive South-West, but Germany could use neither for a deployment to the North
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