Just wanted to agree that they would work well (with head swaps) for Russians, as was mentioned. For Prussians, though, I'm not so sure. The greatcoat that the Russians used is longer than the litewka that the Prussians used. Also, the set has oilcloth covers for the shakos, (which is good) but they are covering a differently shaped shako than what the Prussians used almost forty years before.
Still, it might be a matter of personal choice. Just use different horses.

The greatcoat also buttons? ties? around the legs to give the appearance of coveralls, which is a jolly sensible idea, but I think Napoleonic greatcoats would be more 'flappy'.