the best way to set up the Poles is to base the whole thing on where the Germans have what. It is the most fun when the Germans divert some forces to DoW Yugoslavia, or even better try for a France First, but that strategy is increasingly rare I think in ftf play. With MWiF I think it will make a comeback. A smart German will also commit several of the most mobile corps with at least one MECH/ARM to Denmark to keep the British from landing in force in Frederikshavn.
If they are heavy in East Prussia, sacrificing a unit in Danzig might divert that group for the first impulse, because the Germans will probably want to get the overrun rolls on the two Polish ships.
Lodz is the more difficult city to take due to the extra factory stack...the above set-up gives a two-hex attack on it while it has only one defender, so I would like this set-up as the Germans. You also have to take Lodz to conquer the country, not just Warsaw.
The Germans can only get an 18 point stack for an overrun, since ART can't participate; only the 2-6 tank destroyer is motorized and can participate. If the Germans draw both 8 point ARM (25% chance) they can get to 18 (but only 80% chance of drawing the 2-6 gun). So they can't overrun anything aside from the Polish division....unless they can ground-strike a unit that is out of supply after some manuevering.
A lot can happen in S/O 39...I've never thought of trying to pass on the first turn, I like that, but that might not work for the Chinese if the sun has been shining too much in China. With standard RaW Vichy rules, a lot of German players won't care if they finish Poland on the first turn; what's important is casualties. So I like to maximize the defense of Lodz, the strongest Polish hex. But since HQs and divs are so useful in WiF, I put them in the Pripets to join the CW army in 41 or 42, and the aircraft up near Vilna or somewhere else out of reach of the German set-up. They represent 4 BPs for the CW, and I like to maximize CW lending to France on the second and third turns, so those two pilots are important. I like to fly the CW ATR to re-org a TRS on occasion on the first CW impulse along with a port-strike on Kiel, so it is important to find the planes a really out of the way place to stay until the 2nd Allied impulse, like maybe on the HQ in the swamp. With MWiF divisions created from units the CW won't miss, like the weaker Indian INF corps, the Polish division is a lot less important and I'd put that in Lodz so the Germans need a /S result to take the hex.
Without the HQ and division, the Poles have only two units left over. So I put them either with one in Danzig and one helping to screen Lodz, or if the Germans are weak in Czechosovakia, I put them both in Katowice to possibly get lucky and block the transport of the resources in Poland, or lucky in terms of holding some German units in the south without enough movement to get up to the Warsaw/Lodz area in any rainy weather. Katowice can wrench the German plans the best I think.
I don't think a German player doing repeated attacks on the AI's set-up of Poland could find the perfect set-up to wipe-out Poland. If you use the whole Luftwaffe and 90% of the ground units and the weather is clear for three impulses, Poland is toast with minimal casualties (against that kind of German set-up I would forget Katowice and Danzig and just prevent a first impulse attack on Warsaw). Maybe even in only two impulses. If the Germans use less than that or the weather goes bad, then things get more interesting. But the biggest two variables are the German commitment and the weather, not the Polish set-up, in my opinion.