Me and a friend has played some PoG (20+ games) and decided to try this.
We just played one game and Axis didn't stand a chance.
Randy and I played 3 games and the Axis won every game. The two solo games I played, the Allies won.
* Turn 2 went as expected, advanced the frontline maybe 1-2 spaces deep in russia. (Axis never got further)
That seems a bit slow, but reasonable.
* Starting turn 3, Allied AR1 or AR2 succeeded in trenching all urban spaces in one AR.
Good dice for the Allies.
* Now we fougth on equal terms (both 12-14) over the Urban spaces.
Sun Tzu says, fight where the enemy is not and you are sure to win.
* Allied could play more reinforcement units/RPs while Axis had to spend so much on OPsing only to have Allied defend it --> about turn 6-7 he could push me back.
Your failed operations allowed him time to build up.
* After two winters Axis got -5 and then -6 and from that one pretty much gg.
Allied generally rolled +1/2 drm higher per combat, but even then it wasn't very close. The main problem is the replacements and reinforcements. In the rules it says you can place reinforcements units and replacement LCUs in Urban Centers in a country home region - we interpreted Urban centers as all the urban spaces, so allies easily filled all the trenched urban spaces between the turns with reinforcements and replacements.
There is a counter limit on the trenches.
Is that how it is supposed to work?
It can work that way. You posted in the rules forum, so I suppose this is just a sound check to make sure you didn't miss anything. There is a strategy article in this forum, you should check it out.