I took a deeper look at these when I bought a box. Warlord claim they used information from the curator of a military museum in Poland and that the Vistula Legion were equipped with mainly French kit, rather than Polish and so differed from the Duchy of Warsaw (see above post) in that respect.
The box is a re-issue of Warlord's "mid" French with extra Polish heads. So there's compromise built in when you buy them.
For the Vistula Legion, headgear is the shako for centre coy and voltigeurs with czapka or shako for grenadiers according to the Histofig pic below for 1810-13. Histofig shows sunburst shako plates but the other two show the diamond shaped French plate.