Cities without production can only get to entrenchment level 3 so they won't last long. In 1941 these cities are so far west that the Germans will love having the Russians waste units defending them. The Germans WANT to kill Russian units instead of chasing a retreating enemy.
What will stop the Germans is areas with a contiguous defense line like rivers, terrain belt etc. A city like Zhitomir will not stop the Germans just as Lvov, Vinnitsa etc. are just places for the Germans to kill garrisons.
Russia start the war with no entrenchments so these cities (except maybe cities like (Rzhev and Kaluga) will be overrun before you can even get to entrenchment level 3.
Regarding city size I would say that several of the proposed cities are larger than cities already on the map.
Old:
Pskov: 200k
Petrozavodsk: 260k
Vologda: 285k
Smolensk: 325k
Vitebsk: 340k
Kherson: 330k
Orel: 330k
Proposed new:
Mogilev: 370k
Cherniagov: 300k
Sumy: 280k
Zhitomir: 280k
Rzhev: 70k (but was on the vanilla game map)
Velikiye Luki: 110k
Kaluga: 325k
So only Rzhev and Velikiye Luki were cities that were smaller than most in Russia, but both cities were crucial in the war.
http://en.wikipedia.org/wiki/Battle_for_Velikiye_Luki
Here we see that Velikiye Luki were defended like a fortress and was crucial for both sides to capture.
http://en.wikipedia.org/wiki/Battles_of_Rzhev
The Germans held a salient around Rzhev for quite some time and the area didn't fall during the Russian winter offensive.
Another thing to take into consideration is that city size changed from WW2 to now. So all cities were smaller, some more than others. What we need to look for are what kind of gaming effects do we want. Those cities are more like rail hubs, but they were important rail hubs for the outcome of the war.
Still, nothing is set in stone here so we can easily remove some of the cities if we want to.
Do we know the size of Amman during WW2. Did it have any impact on the warfare there? If no then I don't mind taking it away since Jerusalem is close by.
We have to know that the cities were smaller in general in the north so the rule for how big the cities should be is lower there. E. g. most of the cities in Scandinavia were around 100k or smaller.
Central Europe:
Rostock: 200k (but biggest city in the area that's otherwise empty of nearby cities)
Erfurt: 200k (greater Erfurt 500k)
Graz: 290k
Linz: 270k
Brno: 400k (greater Brno 800k)
Kosice: 240k (second largest city in Slovakia after Bratislava)
Lublin: 350k
So we see that most of the proposed cities are of the same size and you find many on-map cities of the same size. So we don't make a mistake whether we do or don't any new ones. No huge cities are forgotten.
Making a new terrain type (town or rail hub) is nothing that I recommed at the moment. Maybe we could consider lowering the defensive bonuses for cities without production? They can have max 3 entrenchment so maybe the values could be lower while they have entrenchment above 0. That would simulate having a town and not a city.
I could even make code so a city without production is called a town although it's treated as a city game wise. Then I don't need to change the code. So there are several ways we can deal with this. I could even use a different symbol for cities without production so the circle is smaller (since there is no number to write in the center).
What do you think?