ORIGINAL: tumbi1
Ok, I get that, but realistically they couldn't move that many units that far in such a short time frame. As I said, I can't do it, and rightfully so. I have seen similar behavior at times in earlier games, but this example was really striking. It looks to me like the AI picked up all his units from the south and placed them immediately in front of Moscow, and within a week. Moving units to railways, loading them, and railway capacities be damned.
I know the 'units on trains' in the front lines has been fixed, but this is similar behavior, and it seems the AI has unlimited rail capacity to anywhere. It tends to defeat the purpose of cutting railways and expecting to obtain strategic reward for it. Does it do the same with supplies? I once reduced the rail lines feeding Leningrad to a single line, and the subsequent massive troop movements there again in a single week was physically impossible.
nothing to do with the trains issue.
There have been a couple of threads on how the AI behaves but in essence it is poor at anticipation (compared to a player) so gets a huge bonus in terms of reaction. Carlkay has described how you can manage this.
To your question, the AI plays by the rules for resupply/logistics, the problem is it can rotate units in/out of a supply poor region far better than a player can. So in your case, that would have hit the supply situation of the units in Leningrad over time.
In effect, interdiction to hamper movement is a bit of a waste of time, interdiction to hamper logistics might be worth it but its less useful than in a HtH game