General Wagner
Poland 1939
Well, the German leadership has ordered hostilities against a relatively weaker Poland, at the expense of war with the Great Powers of France and Britain. My orders are to subdue a moderately sized and mobilizing state within a space of mere weeks before facing the inevitable onslaught in the west.
Plan:

We intend to push towards the Warta in the north while our main effort is in the south where the capture of Cracow should compromise the Polish southern defence.
September 1st fair
Axis: Our forces need additional reinforcements so we requisition new bombers, artillery, and armour. We subdue the southwest and are poised to move on Cracow directly. Our drive to the Warta is marked by manoeuvring for position and avoiding conflict.
Allies: The Poles respond by strafing Slovakia and hitting our northern light armour, crippling our panzers through constant attacks.
September 2nd, fair
Axis: We commit numbers to the engagement in the north and annihilate half the Polish strength west of the Warta. We engage the Polish airforce, with moderate success, and besiege Cracow. So far the Poles can do little to staunch our advance.
Allies: Polish aircraft fly to the defence of Cracow and the Poles in the north withdraw to Kalisz, but not before inflicting heavy losses on our infantry.
September 3rd, fair
Axis: With Luftwaffe help we subdue west of the Warta and Cracow is soon to fall. Polish fighter cover is at last worn down but their bombers remain a serious threat.

Allies: As expected the Polish bombers hit our light armour very hard, but these aircraft lack fighter escorts…
September 4th, fair
Axis: The Luftwaffe at last is able to engage the Polish bombers and inflicts heavy losses. Cracow falls to our massed assaults and we tentatively cross the Warta in the central front. Depending on the Polish counter we are ready to launch stage 2 of the invasion.
Allies: The Poles deploy light tanks at Lodz and withdraw what remains of their aircraft there too.
Plan stage 2:

Our intentions are to advance on multiple fronts and bypass Polish strongpoints.
September 5th, fair
Axis: We move prematurely on Lodz and suffer serious losses. We do however catch Polish armour in Sandermiez and destroy them with careful infantry assaults. The Polish airforce is finally neutralized.
Allies: Remarkably our troops near Lodz withstand heavy counter-attacks without heavy losses.
September 6th, fair
Axis: We face determined defenders on all fronts bar our daring far eastern then northern hook.

The Lodz situation is too precarious so we withdraw and instead capture Rodomsko in the centre.
Allies: The Poles reinforce Lodz and buy time for France & Britain.
September 7th, fair
Axis: Again we are held up at Lodz and Radom, although we do capture air fields in the east and Kutno in the north. Our bombers do manage to finish off the Polish armour.
Allies: Polish cavalry hit our light panzers and despite the newspaper propaganda their troops accounted for themselves very well.
September 8th, fair
Axis: We break through Radom at last and approach Warsaw from the south and southeast. The Poles have impressive air defences there.
Allies: An artillery barrage from Warsaw, but otherwise little.
September 9th, fair
Axis: The attack on Warsaw begins but the Poles hold their lines and inflict a series of minor victories against our forces.
Allies: The Poles drive us back after numerous attacks, but they in turn take moderate losses. Fortress guns north of Warsaw rake our advance panzers.
September 10th, fair
Axis: Our forces are getting worn down, but we are within a whisker of victory.

But we’re unable to crack the defences…
Allies: More bombardments and counter-attacks again drive us back.
September 11th, fair
Axis: One more series of assaults… and Warsaw is over-run!
Allies: There are no available troops to drive us from the capital – we have secured a decisive victory!